Systems and methods to authenticate users and/or control access made by users based on enhanced digital identity verification

ABSTRACT

A graphlet is extracted from a relation graph for digital identity verification. The relation graph contains data element nodes collected about access activities, such as user access context, payment instrument, address, device information, etc. The graph can be examined to identify node groups in demarcation areas. Nodes outside of the demarcation areas represent data elements of a user; and the data elements in the demarcation areas may or may not be of the user in general. The system determines a matching score between the nodes outside of the demarcation areas and the nodes in a demarcation area. The nodes in the demarcation area are attributed to the user if the matching score is above a threshold. The nodes attributed to the user are combined as the graphlet showing the data elements of the user and used in user authentication and/or access control via electronic signature.

RELATED APPLICATIONS

The present application claims priority to Prov. U.S. Pat. App. Ser. No.62/491,039, filed Apr. 27, 2017 and entitled “Systems and Methods forEnhanced Digital Identity Verification”, the entire disclosure of whichis hereby in incorporated herein by reference.

The present application relates to U.S. patent application Ser. Nos.15/464,193, 15/464,153, and 15/464,141, filed Mar. 20, 2017, the entiredisclosures of which applications are hereby incorporated herein byreference. The present application also relates to U.S. Pat. App. Pub.Nos. 2010/0293094, 2011/0251951, 2015/0324802, 2016/0063500, and2016/0071108, and U.S. patent application Ser. No. 14/938,593, filedNov. 11, 2015, Ser. No. 14/949,305, filed Nov. 23, 2015, Ser. No.15/255,034, filed Sep. 1, 2016, 62/336,059, filed May 13, 2016, and62/402,076, filed Sep. 30, 2016, the entire disclosures of whichapplications are hereby incorporated herein by reference.

FIELD OF THE TECHNOLOGY

At least some embodiments disclosed herein relate generally toauthentication of users on a computer network and more particularly, butnot limited to, access control of users of access tokens used on thecomputer network.

BACKGROUND

The identity of a user in computerized access is typically authenticatedbased on the verification of a piece of information that can be shown tobe in possession by an authorized user but is difficult for others toproduce.

For example, an authentication credential in the form of a user name anda password is typically used in computer-based systems to authenticate auser. When the credential received from a user matches with the storedcredential, the user is provided with the requested access to resourcesand/or privileges associated with the credential in a computer system.Authentication credentials may be in the form of secret data, securityquestions and answers, encryption keys, biometrics (e.g., fingerprints),etc.

However, there are risks of fraudulent use of authenticationcredentials, which may be stolen or hacked.

Further, in some computer systems, authentication credentials may not beconnected to the real identities of the users as known in the society.In some systems, the lack of association between the authenticationcredentials and the real user identities is intentional to allowanonymous access and/or pseudonymous access. However, in some instancesit may be desirable to deny access by certain users based on their realidentities.

There is a challenge to authenticate users for computerized access andminimize the risk of fraudulent and/or illegal access at reduced costs.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments are illustrated by way of example and not limitation inthe figures of the accompanying drawings in which like referencesindicate similar elements.

FIG. 1 shows a computer system in which user authentications methods ofvarious embodiments disclosed herein can be performed.

FIG. 2 shows a user device via which user authentications methods of atleast some embodiments disclosed herein can be performed.

FIG. 3 shows a computing site, access on which can be controlled viauser authentications methods of at least some embodiments disclosedherein.

FIG. 4 shows a controller for user authentication and/or access controlaccording to at least some embodiments.

FIG. 5 shows a method to control access based on electronic signaturesaccording to one embodiment.

FIG. 6 illustrates the generation of a relation graph for userauthentication and/or access control according to at least someembodiments.

FIG. 7 illustrates a portion of a relation graph related to a useridentity according to one embodiment.

FIG. 8 illustrates a portion of a relation graph connecting differententities and attributes according to one embodiment.

FIG. 9 illustrates a portion of a relation graph related to an activityaccording to one embodiment.

FIG. 10 shows a method for access control based on elements in a portionof a relation graph extracted for an activity according to oneembodiment.

FIG. 11 shows a method for access control based on matching graphlets ofa relation graph according to one embodiment.

FIG. 12 shows a method for authenticating a user entity for accesscontrol based on matching graphlets of a relation graph according to oneembodiment.

FIGS. 13 and 14 illustrate monitoring a growth rate of a cluster in arelation graph for access control according to one embodiment.

FIG. 15 shows a method for access control based on a growth rate of acluster in a relation graph according to one embodiment.

FIG. 16 illustrates a system for user authentication using an identityservice according to one embodiment.

FIGS. 17 and 18 show methods for user authentication using an identityservice according to one embodiment.

FIG. 19 illustrates an example of a network of related identities of oneembodiment.

FIG. 20 shows a method of user authentication based on a network ofidentities according to one embodiment.

FIG. 21 shows a method to control access based on a network ofidentities according to one embodiment.

FIG. 22 illustrates an example of a graph of data elements related toaccess activities according to one embodiment.

FIG. 23 shows a method of user authentication based on adding an elementto a relation graph according to one embodiment.

FIG. 24 shows a method of access control based on a graph scoreaccording to one embodiment.

FIG. 25 shows a computing apparatus that can be used to implement thedevices, sites, controllers and/or servers discussed in the presentdisclosure.

FIG. 26 shows a block diagram of a computing infrastructure associatedwith certain embodiments of the present disclosure.

FIGS. 27-32 illustrate some graphs of data elements for enhanced digitalidentity verification.

FIG. 33 shows a method for enhanced digital identity verification.

DETAILED DESCRIPTION

The following description and drawings are illustrative and are not tobe construed as limiting. Numerous specific details are described toprovide a thorough understanding. However, in certain instances, wellknown or conventional details are not described in order to avoidobscuring the description. References to one or an embodiment in thepresent disclosure are not necessarily references to the sameembodiment; and, such references mean at least one.

At least some embodiments disclosed herein perform user authenticationand/or access control based on contextual information related to variousinstances of accesses to reduce fraudulent activities. The userauthentication and/or access control methods can be used in combinationwith traditional authentication methods that require authenticationcredentials and can be used independent from the traditionalauthentication methods.

FIG. 1 shows a computer system in which user authentications methods ofvarious embodiments disclosed herein can be performed.

In FIG. 1, a set of computing devices (e.g., 121, 123, . . . , 125, . .. , 129) can be used by different persons (e.g., 131, 133, . . . , 139)to gain access, over the computer network (100), at computing sites(e.g., 111, 113, . . . , 119). The computing sites may provide differentand/or related services.

A user (e.g., person (131)) may use multiple devices (e.g., 121, 123, .. . , 125) to access some of the services provided on the sites (e.g.,111, 113, . . . , 119).

A computing device (e.g., 125) may be used by different persons (131 and133) to access a same set or different sets of services provided on thecomputing sites (e.g., 111, 113, . . . , 119).

The devices (e.g., 121, 123, . . . , 125, . . . , 129) may be used atdifferent geographical locations and/or network locations and can berelocated to different geographical locations and/or network locationsfor continued access by the same persons and/or by different persons atdifferent time instances.

Typically, an access token is provided to a user to indicate the accessprivileges of the user. The presentation of an access token by a userrepresents an access request, transaction, or session made in accordancewith the predefined privileges associated with the token. For example,an access token may represent an account based on which certaininformation or asset may be accessed, such as applications, games,emails, advices, account details, entertainments, funds, virtualcurrencies, and/or other benefits. When the request for access made viathe access token is granted, the user may start a session, an activity,or a transaction to access privileged information, functionality of acomputing site, and/or other assets. For example, the access may allowthe user to run an application, consume information/data, transmit amessage to another user, make an asset exchange/trade, and/or make orreceive a payment, etc.

At least some embodiments disclosed herein use the contextualinformation received in connection with access requests; and the dataelements in the contextual information are correlated and/or connectedto each other to provide enhanced capability of user authorization andaccess control.

Contextual information of an access request generally includeinformation that can be collected during the processing of the accessrequest and/or during the session, activity, or transaction where theaccess is provided as a result of the access request being granted.Examples of such contextual information includes the identification ofan access token used to make the access request, the identificationinformation of the device from which the access token is received, thenetwork identification information of the device at the time the accessrequest is received, the geographical location of the device determinedby its location determination unit (e.g., a global positioning system(GPS) receiver), characteristics of user input activities during thesession, activity, or transaction, etc.

In some instances, the access made by a user (e.g., 131) using a device(121) includes the interaction of the user (e.g., 131) with one or moreother users (e.g., 139) who use other devices (e.g., 129). Thus, thecontextual information may further include the information collectedabout the other devices (e.g., 129) used by the other users (e.g., 139).

The correlation and/or connection of the contextual information ofaccesses made using various access tokens on various user devices canenhance the identity recognition of the persons behind the accessrequests and improve user authentication to prevent fraudulent and/orillegal accesses.

For example, a controller (101) in FIG. 1 is configured in oneembodiment to communicate with the computing sites (111, 113, . . . ,119) and use the contextual information to perform enhanced userauthentication and/or access control that further reduces fraudulentactivities on the computing sites (111, 113, . . . , 119). The computingsites (111, 113, . . . , 119) may optionally implement additional userauthentication and/or access control methods (e.g., using authenticationcredentials) independent from the user authentication and/or accesscontrol implemented on the controller (101).

In some instances, at least some of the accesses are made on a peer topeer network of some of the devices (121, 123, . . . , 125, . . . ,129). The peer to peer network may be configured to allow anonymousaccess and/or pseudonymous access. Through correlation/connection ofdata elements of contextual information of accesses made on theanonymous/pseudonymous network(s) and respective data elements ofcontextual information of accesses made on other networks, the userauthentication capability of the controller (101) can be improved.

In some instances, the controller (101) is implemented as an independentcomputing site, or a collaborative module implemented within or amongthe computing sites (111, 113, . . . , 119).

FIG. 2 shows a user device via which user authentications methods of atleast some embodiments disclosed herein can be performed. For example,one or more of the user devices (121, 123, . . . , 125, . . . , 129) canbe implemented in a way similar to the implementation of the user device(120) illustrated in FIG. 2, with or without modifications.

In FIG. 2, the device (120) includes memory (160) storing software(161), at least one network interface (143) to communicate via a network(100), one or more microprocessors (145) to execute the software (161)stored in the memory (160). The software (161) typically includes anoperating system and one or more applications running on top of theoperating system. The memory (160) stores the software identifiers (167)that identify at least some of the software (161) configured in thememory (160), hardware identifiers (165) identifying hardware componentsof the device (120), and other information, such as usage statistics(169) of the hardware and/or software (161) of the device (120), andapplication data (163) generated by and/or configured for theapplications executed by the microprocessors (145) in the device (120).

In some instances, the device (120) optionally further includes positiondetermination devices (e.g., GPS receiver) to determine its currentlocation (147), sensors to generate measurements (e.g., backgroundnoise, user biometrics input, images, etc.).

Some of the computing sites (e.g., 111, 113, . . . , 119) may requirethe registration of user information (150) (e.g., the name (151) of theregistered user of the access token (141), a street address (153) of theuser, a phone number (155) of the user) in order for the user to obtainand/or use the access token (141). In some instances, some of the userinformation (150) is required to facilitate the access to the serviceprovided by a respective site, such as making a purchase to have an itemshipped to an address. In an anonymous/pseudonymous site or network,user registration may be not required; and some or all of the userinformation (150) may be not available in the context of an access onthe anonymous/pseudonymous site or network. Different computing sites(e.g., 111, 113, . . . , 119) may be configured to use different accesstokens (e.g., 141).

In general, different persons (e.g., 131 and 133) may share an accesstoken (e.g., 141) on one or more devices (e.g., 123, 125). The sametoken (141) may be used on different devices (e.g., 123, . . . , 125) bythe same person (131) or different persons (e.g., 131 and 133). Thus, itis a challenge to prevent fraudulent uses of the access tokens (e.g.,141).

At the time an access is made using the access token (141) (e.g., in theform of an account identifier or a resource identifier), the device(120) of one embodiment is configured to provide contextual data relatedto the access to the controller (101) (e.g., directly, or indirectly viaa computing site where the access is made). The contextual data mayinclude some of the data collected and/or stored in the memory (160),such as the hardware identifiers (165), the software identifiers (167),the usage statistics (169), the location (147), the user information(150), etc. In a way the contextual data represents an electronicsignature of the device (120) at the time of the access and/or a set ofuser attributes of the user using the token (141) to gain the access.The controller (101) makes use of the contextual information to improveuser authentication and/or access control as discussed further below.

For example, data associated with an access made using an access tokencan be collected to build a representation of the user who is associatedwith the access token in the access (e.g., a transaction). The dataassociated with the access can be seen in the network and/or the accessactivity and analyzed and/or used to create an electronic signature ofthe user. Exemplary attributes of such data include, but are not limitedto, browser fingerprints, computer fingerprints, IP addresses,geographic IP location information, information associated with apayment, and/or a typing pattern when entering data in fields related tothe payment or other fields. Browser fingerprints may include attributesassociated with an individual's browser that may be extracted usingstandard interfaces. For example, browser fingerprints may includecharacteristics such as user agent (includes browser and operatingsystem), screen resolution, software plug-ins (in a manageable state),time zone, system language, whether Java is enabled, whether cookies areenabled, sites visited, and/or IP address. The present disclosurecontemplates that matching browser fingerprint characteristics in asubsequent interaction with those collected during a prior interactionmay indicate a high probability that the same browser and/or device wasused in both the prior and subsequent interactions.

Some exemplary computer fingerprints may allow a determination ofwhether a physical machine is the same as one that has been seen in thepast. Computer fingerprints may include, for example, processorcharacteristics (e.g., model number, version, speed, cache size serialnumber, etc.), memory size of the machine, values that are loaded at keylocations, values of the registry of the loaded operating system,Ethernet MAC (media access control) address, raw networking and networkinformation (e.g., configuration parameters), loaded programs, and/orlog files. Some exemplary embodiments may utilize performance onspecified benchmark program fragments, such as by measuring theperformance of a program that includes different characteristicsincluding input/output and CPU (Central Processing Unit) speed. Such anapproach may take into account the other processes running on a user'smachine, the amount of memory, etc., and it may provide reproducibleresults so that it may act as a part of a fingerprint. Exampleinformation associated with an online activity may include behaviorsobserved on entered information (e.g., typing rhythms, billing addressesentered, cards used, passwords or PINs (Personal Identification Number)stored and/or requested), Zip code, full name entered, and/or loadedversus empty fields on entering information (for example, the browsermay have the previously entered values from the last instance of theuser). This can be seen to be entered by the browser rather than typingby the speed of entry of the characters. In some exemplary embodiments,the electronic signature may uniquely identify the user at the samemerchant in future transactions and/or at other merchants where the sameattributes can be seen.

By associating a particular access token and/or a device identity with aknown user identity (e.g., represented by his or her electronicsignature), the controller can determine whether or not the access tokenused in a particular instance of access is known to belong to thecurrent user who is presenting the access token.

In some instances, the lack of correlation between the newly collectedelectronic signature and any previously collected electronic signaturemay be used to identify instances of access that may merit furtherassessment. For example, if the newly collected electronic signaturecorrelates with a known, previously collected electronic signature of adifferent user (e.g., a user other than the user involved in the currentinstance of access), the current access may be flagged for furtherassessment, such as further determination of whether or not fraud isinvolved or whether additional fraud checks need to be performed.

FIG. 3 shows a computing site, access on which can be controlled viauser authentications methods of at least some embodiments disclosedherein. For example, the site (110) illustrated in FIG. 3 may be one ofthe computing sites (11, 113, . . . , 119) illustrated in FIG. 1.

In FIG. 3, the site (110) includes at least one network interface (143)to communicate via the network (100), one or more microprocessors (145)to execute instructions of software configured for user authenticationand/or access control, and memory (160) storing the softwareinstructions and data relates to user authentication and/or accesscontrol.

For example, the access token (141) that may be used by a user on thedevice (120) can be secured at least in part via the credential (173)associated with access token (141). The credential (173) is typicallyused to verify whether the user is in possession of a piece ofinformation associated with the access token (141). For example, thecredential (173) may include a secret (e.g., password, biometrics,passcode, security code) that is assumed to be available only to theauthorized user of the access token (141). For example, the credential(173) may include a public key that can be used to verify the user ofthe device (120) is in possession of a respective private key using apredetermined asymmetric cryptography algorithm. In some instances, theaccess token itself is considered a secret (e.g., an account number)that is used to authenticate the user and/or control access.

In some instances, the computing site (110) requires user registrationto associate the access token (141) with user information (150), such asthe name (151) of the registered user of the access token (141), astreet address (153) of the user, a phone number (155) of the user, etc.However, when the access token (141) is shared by a number of persons(e.g., 131 and 133), the registered user information (150) may notaccurately identify the actual user of a particular instance of anaccess made via the access token (141). In some instances, fraudulentuser information (150) may be used in registration; and in otherinstances, one or more services of the site (110) may be provided viaanonymous/pseudonymous access, and thus the user registration isoptional and/or not performed.

In FIG. 3, the computing site (110) tracks the activity records (171) ofthe accesses made using the access token (141). The activity records(171) include the contextual information collected from the device(e.g., 120) when the accesses are made using the access token (141). Theactivity records (171) can be used in the controller (101) to implementenhanced user authentication and/or access control using methodsdisclosed herein.

In some instances, activity records may be stored in a distributednetwork of devices (e.g., 121, . . . , 129). For example, transactionrecords of cryptocurrency can be implemented as a blockchain in the formof a distributed database that maintains blocks of records and containtimestamp and a secure hash based history to prevent tampering andrevision.

For example, the access may be made on the device (120) using a webbrowser that runs a client code (e.g., a plug-in application, an applet,a script running in a web page) to collect contextual data (e.g., afingerprint of the device (120), available user data related to theaccess). The contextual data for the access is transmitted to the site(110) and/or the controller (101) in connection with the use of theaccess token (141) and stored as part of the activity records (171) thatis specific for the access from the device (120). Some examples ofimplementations to collect the contextual data and its use for userauthentication and access control can be found in U.S. Pat. No.9,471,920, entitled “Transaction Assessment and/or Authentication”, theentire disclosure of which is hereby incorporated herein by reference.

FIG. 4 shows a controller for user authentication and/or access controlaccording to at least some embodiments.

In FIG. 4, the controller (101) includes at least one network interface(143) to communicate on the network (100), one or more microprocessors(145) to execute instructions of software configured for userauthentication and/or access control, and memory (160) storing thesoftware instructions and data relates to user authentication and/oraccess control.

For example, the memory (160) of the controller (101) stores datarepresenting a graph of elements collected in connection with the use ofaccess tokens (e.g., 141).

Based on the activity records (171) received from computing sites (e.g.,111, 113, . . . , 119) and/or the computing devices (121, 123, . . . ,125) on which the access token (141) is used, the controller (101)connects the access token (141) to devices identities (185) of devices(e.g., 121, . . . , 125) from which the access token (141) is receivedfor access, and the user identities (189) of users using the respectivedevices (e.g., 131, 133).

In FIG. 4, a device identity (185) represents a device (e.g., 125) thatis identified by an electronic signature (187) of the device. Theelectronic signature (187) includes data elements, extracted from thecontextual data of an access made using the access token (141), that arecombined to identify a physical device (e.g., 120) from which the accesstoken (141) is submitted from access.

For example, the data elements of the electronic signature (187) mayinclude the hardware identifiers (165), software identifiers (167),configuration data of the software and/or hardware of the device (120),etc.

For example, the data elements of the electronic signature (187) mayinclude one or more of browser fingerprints, computer fingerprints, IPaddresses, phone numbers, ESNs (electronic serial numbers of mobiledevices), IMEIs (international mobile station equipment identity), SIM(subscriber identification module), etc.

The identifications of devices (e.g., 121, . . . , 125) in combinationwith further data specific to users, such as geographic IP locationinformation, emails, SSNs (Social Security number), TINs (taxpayeridentification number), date of birth, activities made in connectionwith the granted access, typing patterns, biometrics, facial image,voice pattern, etc., tell apart the actual users of the access token(141) and/or the devices (e.g., 121, . . . , 125) represented by thedevice identify (e.g., 185).

In general, an access token (141) is connected to a plurality devicesidentities (e.g., 185) corresponding to different physical devices(e.g., 121, . . . , 125) from which the access token (141) is submittedto request access. Each of the devices represented by a device identity(185) having one or more electronic signatures (187) may be used by morethan one person represented by respective user identities (e.g., 189)having the user information (150). Thus, a user identity (189) may beconnected to multiple electronic signatures (e.g., 187) of one or moredevices.

In some instances, some of the user information (150) is obtained viathe user registration process. In some instances, some of the userinformation (150) is obtained via correlating with identificationinformation (e.g., facial images, thumbprints, voice pattern, typepattern, government issued identification number, biometrics,) with userinformation obtain from third party database. In some instances, some ofthe user information (150) is obtained via form data of onlineactivities related the access/services provided via the access token,such as the shipping and/or billing address for online purchases.

In FIG. 4, based on reports on the consequences of providing accessesmade via the access token (141), providing access by receiving accesstoken (141) from devices represented by the device identities (e.g.,185), and providing access to persons represented by user identities(189), the system may generate reputation scores (e.g., 181) for accesstokens (e.g., 141), reputation scores (e.g., 182) for the deviceidentity (185), and reputation scores (e.g., 1830 for the user identity(189). In one embodiment, the reputation score of an access token (141),a device identity (185), or a user identity (198) represents theprobability that an access made via the access token (141), the deviceidentity (185), or the user identity (198) has a undesirableconsequence.

In processing the user authentication and/or access control of aspecific instance of the use of the access token (141), the controller(101) extracts the data fields from the contextual data received inconnection with the instance of the use of the access token (141) anddetermines the matching device identity (e.g., 185) and/or the matchinguser identity (e.g., 189). Based on the degree of matching and thereputation scores of the access token (141), the device identity (e.g.,185) and the user identity (e.g., 189), the controller (101) determinesa trust score for the specific instance of the use of the access token(141). Based on the trust score, the controller (101) authenticates theuser and/or controls the access.

In FIG. 4, the memory (160) of the controller (101) stores one or moreblacklists of fraudulent elements. The controller (101) may furtherauthenticates the user and/or controls the access based on blacklisteddata elements in the graph that are connected to the contextual datareceived from the specific instance of the use of the access token(141).

FIG. 5 shows a method to control access based on electronic signaturesaccording to one embodiment. For example, the method of FIG. 5 can beused in the system illustrated in FIG. 1, with computing devices (121,123, . . . , 125, . . . , 129) implemented as illustrated in FIG. 2 andsites (e.g., 111, 113, . . . , 119) implemented as illustrated in FIG.3, and a controller (101) implemented as illustrated in FIG. 4.

In FIG. 5, the controller (101) is configured to store (201) contextualdata identifying user attributes (e.g., user information (150)) anddevice attributes (e.g., electronic signatures (187)) of respectiveusers (e.g., 131, 133, . . . , 139) accessing a system from computingdevices (e.g., 121, 123, . . . , 125, . . . , 129) using an access token(e.g., 141). The system has one or more computing sites (111, 113, . . ., 119) that may provide separate services. The controller (101)associates the device attributes with respective entity representationsof devices (e.g., 121, 123, . . . , 125, . . . , 129) and the userattributes with respective entity representation of respective persons(e.g., 131, 133, . . . , 139).

In response to receiving (203) a set of user attributes and deviceattributes associated with a request to access the system (e.g., thecomputing site (110)) using the access token (141), the controller (101)determines (205) an identity (e.g., 185) of a device of the request fromthe device attributes and authenticates (207) an identity of a user ofthe request based on matching the set of user attributes and deviceattributes to one of the user entities (e.g., 189) that are associatedthe access token (141) and the device entity (185). The computing site(110) may optionally use the credential (173) to preliminaryauthenticate the user. The set of user attributes and device attributestransmitted, as the contextual data specific for the current requestmade using the access token, to the controller (101) (e.g., via the site(110), or directly from the user device (121, 123, . . . , 125, or129)).

The controller (101) is further configured to evaluate (209) a trustscore based on a degree of matching between the set of user attributesand device attributes and the respective attributes of the matched userentity (189), a reputation score (183) of the identity (189) of the user(e.g., 131, 133, . . . , or 139), a reputation score (181) of the accesstoken (141), a reputation score (182) of the identity (185) of thedevice, and a degree of strength of a connection between the accesstoken (141) and the device entity (185).

Based on the trust score, the controller (101) approves, rejects orfurther investigates (211) the request to access the system.

For example, the access token (141) may be an online account foraccessing an online account having services provided by a computing site(e.g., 111, 113, . . . , 119), an email address for accessing emails, auser name for accessing instant messages, an account number for onlineaccess of a social networking site, an account with an online merchantto purchase items or services, an account number to make a payment, atoken of a cryptocurrency for a transaction, etc.

In one embodiment, each attribute is assigned a predetermined weight. Adegree of matching is computed in the form of a matching score that is afunction of the sum of the weights of the matched attributes (Wa), thesum of the weights of the mismatched attributes (Wb), the sum of theweights of the attributes that have no data for the current accessrequest (Wc), and the sum of the weights of all attributes (Wd). Forexample, the matching score of one embodiment is computed as a functionof (Wa*Wa−2*Wb−Wc)/(Wd*Wd).

The user entity (189) having the highest matching score for the currentaccess request can be considered the user entity (189) of the currentaccess request. The matching can be performed based on user attributessuch as name of the user, billing and/or shipping address of the user,phone number and/or email address of the user, typing rhythm of theuser, account name of the user, device fingerprint, browser fingerprint,IP Address, Geo-location of the IP address, Geo-location of thebrowser/device, etc.

For example, a browser fingerprint may include at least one of a useragent, a screen resolution, a software plug-in, a time zone, a systemlanguage, whether Java is enabled, whether cookies are enabled, a sitevisited, and an IP address.

For example, a fingerprint may include at least one of a processorcharacteristic, a memory size of the machine, a value that is loaded ata key location, a value of a registry of a loaded operating system, anEthernet MAC address, raw networking information, network information, aloaded program, and a log file.

Examples of network information include a network provider, whether anIP address is consistent with a known IP address, a geographicalproximity of an address registered with a payment instrument and the IPaddress as determined by an IP to Geo-location service, whether or not aproxy is in use, whether a known bad IP address is in use, and whetherthe IP address is associated with a service provider who was associatedwith the user in the prior transaction.

Further examples of the computing of a matching score and the rules forapproving, rejecting or further investigating (211) the request toaccess the system can be found in U.S. Pat. No. 9,471,920, entitled“Transaction Assessment and/or Authentication”, the entire disclosure ofwhich is hereby incorporated herein by reference.

FIG. 6 illustrates the generation of a relation graph for userauthentication and/or access control according to at least someembodiments. For example, the relation graph can be generated using thecontextual information discussed in connection with FIG. 4.

In FIG. 6, different access tokens (e.g., 221, . . . , 223) can be usedby users (e.g., 131, 133, . . . , 139) of different devices (121, 123, .. . , 125, . . . , 129) to access various networks, such as anonymousnetwork (231), pseudonymous network (233), user-identified network(235).

For example, the user-identified network (235) may include one or moresites (e.g., 110) that require user registration to provide services.The user registration may or may not include a level of effort inverifying the user information (150). Thus, the user information (150)obtained via the registration process may have varying degrees ofreliable in accuracy.

The anonymous network (231) and pseudonymous network (233) generallyprovide enhanced privacy protections for their users by allowing variousdegrees of anonymity in activities on their network. Thus, theavailability of the user information (150) is generally low for therespective activities.

In FIG. 6, the activity records (225, 227, 229) of the access activitiesmade using the tokens (221, . . . , 223) are combined to generate arelation graph (239) that links the device entities (e.g., 185) and userentities (189) through common attributes (187) in contextual data toreveal the connections among the entities (185, 189) and tokens (e.g.,221, . . . , 223), as further discussed below.

For example, online activities and/or accesses may involvecryptocurrency, such as Bitcoins. Bitcoins transactions can be performedpseudo-anonymously (see https://en.wikipedia.org/wiki/Cryptocurrency),where two users can transfer Bitcoins to each other without revealingthe identity of either of them. The transaction is cryptographicallysigned to ensure that the transaction took place, and there is a publicrecord of such transaction that can be verified by all players on theBitcoin infrastructure. Thus, the activity records of accesses made onsuch sites (e.g., Bitcoin Exchange) may not have real useridentification information.

A cryptocurrency is a medium of exchange designed around securelyexchanging information over a computerized network, which is madepossible by certain principles of cryptography. Cryptocurrencies arebased on specifications regarding the use of currency which seek toincorporate principles of cryptography to implement a distributed,decentralized and secure information economy. An example ofcryptocurrency is Bitcoin, which is used in a peer-to-peer paymentsystem. The payments in the system are recorded in a public ledger. TheBitcoin system is a decentralized virtual currency, because it has nocentral repository and no single administrator. In contrast, FIAT moneyis money which derives its value from government regulation or law. Itdiffers from commodity money, which is based on a good, often a preciousmetal such gold or silver, which has uses other than as a medium ofexchange.

When users want to exchange their Bitcoins to FIAT currency (or FIATmoney) they would have to use a Bitcoin Exchange or a BitcoinWallet-hosting company that enables exchanging Bitcoins into FIATcurrency. Such exchanges are regulated by governmental bodies in manycountries to capture information about the users, via an activity knownas “Know Your Customer” or KYC. Thus, the activity records of accessesmade on such sites (e.g., Bitcoin Exchange) have user identificationinformation.

The relation graph (239) connects the elements from various networks(225, 227, 229) and allows the controller (101) to monitor activitiesinvolving anonymous and/or pseudonymous accesses for monitoring offraudulent accesses. For example, using the controller (101),organizations/individuals that enable exchanging Bitcoins for FIATcurrency, and vice versa can monitor “financial” transactions forpotential money laundering activities and/or other suspicious activity,such as fraud.

In one embodiment, a statistical analysis of the activities records(225, 227, 229) is performed to identify a cluster of activities thatare naturally grouping together for being close to each other based onattributes of the activities (e.g., the data items describing therespective activities in the activity records). For example, a clusterof Bitcoin (or other currency) addresses and/or transactions can beidentified for grouping the respective activity records together. Thetransactions and/or Bitcoins in the cluster are statistically relatedbased on the available data associated with them. The grouped activityrecords can be assembled into a relation graph for the cluster, whichcan be used in various user authentication and access control methodsdisclosed herein. Alternatively, the activity records (225, 227, and229) can be assembled into a large relation graph (239) from whichgraphlets of interest can be extracted.

For example, when an individual is known or suspected to be involvedwith fraudulent or illegal access, the access tokens, device identitiesand/or user identities used by the individual can be identified. When acluster of activities includes the access tokens, device identitiesand/or user identities used by the individual, the other individualsinvolved in the cluster may be shown to be related and potentiallyinvolved in illegal or fraudulent access.

Similarly, if a cluster is observed, first, as potentially tied tofraudulent or illegal access, the relation graph (239) can be used tomap the activities to real people as identified in the user-identifiednetwork (e.g., persons submitting the transactions in Bitcoinexchanges). This establishes a correlation of attributes which areseemingly unrelated. The real people involving in the related activitiescan be investigated as potentially being involved with the fraudulent orillegal access. The attributes involved with the related activities(e.g., transactions obtained via the KYC and the submitted data) can bescrutinized in other activities as then being related to questionableactivities.

FIG. 7 illustrates a portion of a relation graph related to a useridentity according to one embodiment. Via contextual data received inconnection with the access requests made using the tokens, a useridentity (241) having the user attributes can be linked in a relationgraph to activities (255) of the user identity (241), the tokens (253)used by the user identity (241), the identities (257) of devices fromwhich the tokens (253) have been submitted by the user identity (241) torequest accesses, the device attributes (259) of the devices having thedevice identities (257). Some of the user attributes (251) are obtainedas activity-specific data in connection with respective activities. Someof the user attributes (251) are obtained from user registration processand/or third party database. Some of the device attributes (259) areobtained as contextual data of the activities (255).

FIG. 7 is provided to generally illustrate the connections among some ofthe elements. In some instances, certain connections are missing for auser entity; and in other instances, additional connections may bepresent.

In FIG. 7, one connection is used to illustrate the connection between agroup of elements (e.g., tokens (253)) and the user identity (241) oranother group of elements (e.g., activities (255)). In general, eachelement (e.g., token (141)) may be linked to other elements in the graphin a way different from other elements in the group. For example, agiven token (141) may be connected to a subset of activities (253)different from other subsets of activities (255) to which another token(e.g., 221) in the group (e.g., tokens (253)). Thus, the illustrationprovided in FIG. 7 does not represent the specific connections amongdifferent items represented by the groups of items.

Common elements of portions of the graph related to different usersidentities can link the portions and establish connections between useridentities, device identities, access tokens, etc. The connectionrelations identified in the graph can be further used for userauthentication and/or access control.

FIG. 8 illustrates a portion of a relation graph connecting differententities and attributes according to one embodiment.

In FIG. 8, a user identity (261) in the graph is, for example, connecteddirectly to a user attribute (271), a token (273) used in an activity(275) on a device having the device identity (277), where the device hasthe attribute (279).

In FIG. 8, an activity (275), for example, involves two access tokens(273 and 283) (e.g., for an interaction, exchange, or transactionbetween two persons); and thus, the activity (275) connects to bothtokens (273 and 283).

In FIG. 8, the token (283) is, for example, used by a user identity(281) (e.g., in an activity that may be different from the activity(275)), which uses a further token (289) in a further activity.

In FIG. 8, the token (283) is used in the context of a device identity(285) and thus links the user identity (281) to the device identity(285).

In FIG. 8, since the token (287) used by the user identity (291) issubmitted from a device having the device entity (277), the token (287)connects the device entity (277) to the use identity (297).

Thus, FIG. 8 illustrates examples of growing the relation graph based onaggregating contextual data from different access instances made usingvarious devices by various persons. However, the relation graph is notlimited to the examples discussed above and/or the specific connectionsillustrated in FIG. 8.

After the relation graph (239) is established, a portion of a graph(e.g., a graphlet) can be extract from the graph for the analysis of anaccess request. For example, a graphlet for the activity (275) can beextract by retrieving elements connected to the activity (275) up to apredetermined number of degrees of separate in the graph, as illustratedin FIG. 9.

FIG. 9 illustrates a portion of a relation graph related to an activityaccording to one embodiment.

For example, in FIG. 8, the activity (275) is directed connected to thetokens (283 and 273), the user identity (261) and the device identity(277). Thus, the tokens (283 and 273), the user identity (261) and thedevice identity (277) are retrieved as the connected elements of thefirst degree in the graphlet illustrated in FIG. 9.

In FIG. 8, the device identity (285) and the user identity (281) areconnected to the token (283). Thus, the device identity (285) and theuser identity (281) are retrieved as the connected elements of thesecond degree to the activity (275) via the token (283) in the graphletillustrated in FIG. 9.

Similarly, the user attribute (271) and the device attribute (279) areconnected as second degree elements to the activity (275) via the useridentity (261); and the token (287) is connected as a second degreeelements connected to the activity (275) via the user identity (261).

In FIG. 9, the graphlet is retrieved in the form of a tree rooted at theactivity (275); and the connections between any elements having the samedegree of connections to the root (e.g., the connection between thetoken (273) and the user identity (261) as illustrated in FIG. 8) isdiscard. Alternatively, such connections may also be imported into thegraphlet for the activity (275) for further analysis.

In FIG. 9, the level of connected elements (e.g., breadth or depth)retrieved from the graph for the graphlet is determined by the thresholddegree of separate in the graph between the root element (e.g., activity(275)) and the retrieved elements. The minimum number of directconnections required from a path from an element to another is thedegree of separation of the two elements in the graph. In FIG. 9, theelements up to a predetermined number of degrees of separation (e.g.,two) are retrieved and organized in a form of a tree rooted at theactivity (275). The predetermined number of degrees of separation can beincreased to increase the breadth or depth of the extraction of thegraphlet.

In some instances, the risk of the rooted element (e.g., activity (275))is evaluated based on the risks of the elements in the extractedgraphlet and/or their degrees of separates to the rooted elements. Forefficiency, a graphlet is initially extracted for analysis according toa first degree of separation. When the risk level determined from ananalysis of the graphlet is within a predetermined range, the breadth ofgraphlet extraction is expanded/increased to a second degree ofseparation for a further, comprehensive analysis. The expansion can berepeated as necessary and/or useful.

FIGS. 8 and 9 illustrate the extraction of a graphlet rooted at anactivity (275) according to a predetermined degree of separate in therelation graph (239). The extracted graphlet can be analyzed todetermine risk associated with the rooted element (e.g., the activity(275)) based on risks associated with the elements in the extractedgraphlet.

In general, the extraction of a graphlet can be rooted at other types ofelements in the relation graph. For example, extracting a graphletrooted at the user identity (189) can be performed for an analysis ofrisks associated with the user identity (189); an extracted graphletrooted at the device identity (185) can be used for an analysis of risksassociated with the device identity (185); and an extracted graphletrooted at the access token (141) can be used for an analysis of risksassociated with the access token (141).

Further, in some instances certain types of elements can be eliminatedby directly connecting elements that are initially connected by theelements of the types to be eliminated. A replacement connection can beused to replace two connections from an eliminated element to twopreviously indirectly connected elements; and the replacement can beoptionally assigned a connection strength indicator reflecting thestrength of the two replaced connections made via the eliminatedelement. For example, all elements other than user identities may beeliminated to generate a reduced graph that connects only useridentities with connections having connection strength indicatorsindicating user identities directed connected with each other in thereduced graph. For example, a reduced graph can be generated to haveonly user identities, device identities, and access tokens. For example,another reduced graph can be generated to have only user identities, anddevice identities (or access tokens). For example, a further reducedgraph can be generated to have only device identities and access tokens.

FIG. 10 shows a method for access control based on elements in a portionof a relation graph extracted for an activity according to oneembodiment. For example, the method of FIG. 10 can be implemented in acontroller (101) of FIG. 4 in a system illustrated in FIG. 1; therelation graph can be constructed in a way as illustrate in FIGS. 6, 7and 8; and the portion can be extracted for an activity in a way asillustrated in FIGS. 8 and 9.

In FIG. 10, the controller (101) is configured to receive (301) dataidentifying accesses made online, using access tokens (e.g., 141, 221, .. . , 223), from devices (122, 123, . . . , 125, . . . , 129) to accessresources in computer networks (e.g., 231, 233, 235). The received datamay include activity records (171, 225, 227, 229) of the accessactivities and/or contextual data associated with the activities, suchas device attributes (259) representing electronic signatures (187) ofthe respective devices (122, 123, . . . , 125, . . . , 129), and theuser attributes (251) containing user information (150).

The controller (101) organizes (303) the data in a graph form linkingelements including the access tokens (e.g., 141, 221, . . . , 223, 253,273, 283, 287, 289), user entities (e.g., 189, 241, 261, 281, 291),device entities (e.g., 185, 257, 277, 285), user attributes (e.g., 150,251, 271), device attributes (e.g., 187, 259, 279) based on theirconnections in the data, such as the relation graph (239) havingportions illustrated in FIGS. 7, 8, and 9.

In response to receiving (305) an indication of a request for accessmade using a particular access token (273) on a device (e.g., 121, 123,. . . , 125, . . . , or 129), the controller (101) extracts (307), fromthe graph (e.g., 239), a set of elements connected to the request up toa predetermined number of connections in the graph (239). For example,after the contextual data of the request for access is added to therelation graph (239), the request for access corresponds to the activity(275) in FIG. 8; and a graphlet rooted in, or centered at, the activity(275) is extracted as in FIG. 9 up to a predetermined degree of separatein the relation graph (239).

The controller (101) compares (309) the set of elements (e.g., in theextracted graphlet illustrated in FIG. 9) to one or more predeterminedlists (e.g., blacklists) to identify matches. Based on a result ofmatching the set of elements (e.g., the graphlet of FIG. 9) against thelists (e.g., blacklists (181)), the controller (101) approves, rejects,or further investigates (311) the request (e.g., represented by theactivity (275)).

For example, the controller (101) counts the number of elements in thegraphlet of FIG. 9 that are on a first list. If the count is above afirst threshold, the controller (101) rejects the request (or furtherinvestigates the request).

If the count is less than the first threshold, the controller (101)counts the number of elements in the graphlet of FIG. 9 that are on asecond list. If the counted element common to the second list and thegraphlet is below a second threshold (which may or may not be the sameas the first threshold), the controller approves the request; otherwise,the controller (101) rejects the request (or further investigates therequest).

Other examples and details of the application of the technique thatcontrols access based on comparing elements from a graphlet to one ormore predetermine lists can be found in U.S. Pat. App. Pub. No.2016/0071108, the entire disclosure of which is hereby incorporatedherein by reference.

FIG. 11 shows a method for access control based on matching graphlets ofa relation graph according to one embodiment. For example, the method ofFIG. 11 can be implemented in a controller (101) of FIG. 4 in a systemillustrated in FIG. 1; the relation graph can be constructed in a way asillustrate in FIGS. 6, 7 and 8; and graphlets can be extracted for anactivity in a way as illustrated in FIGS. 8 and 9.

In FIG. 11, the controller (101) is configured to receive (331) dataidentifying accesses made online, using access tokens (e.g., 141, 221, .. . , 223), from devices (122, 123, . . . , 125, . . . , 129) to accessresources in computer networks (e.g., 231, 233, 235). The received datamay include activity records (171, 225, 227, 229) of the accessactivities and/or contextual data associated with the activities, suchas device attributes (259) representing electronic signatures (187) ofthe respective devices (122, 123, . . . , 125, . . . , 129), and theuser attributes (251) containing user information (150).

The controller (101) organizes (333) the data in a graph form linkingelements including the access tokens (e.g., 141, 221, . . . , 223, 253,273, 283, 287, 289), user entities (e.g., 189, 241, 261, 281, 291),device entities (e.g., 185, 257, 277, 285), user attributes (e.g., 150,251, 271), device attributes (e.g., 187, 259, 279) based on theirconnections in the data, such as the relation graph (239) havingportions illustrated in FIGS. 7, 8, and 9.

After receiving (335) an indication of a request for access made using aparticular access token (e.g., 141) on a device (e.g., 121, 123, . . . ,125, . . . , or 129), the controller (101) extracts (337), from thegraph (239), a set of elements connected to the request up to apredetermined number of connections in the graph (239). For example,after the contextual data of the request for access is added to therelation graph (239), the request for access corresponds to the activity(275) in FIG. 8. A graphlet rooted in, or centered at, the activity(275) is extracted as in FIG. 9 up to a predetermined degree of separatein the relation graph (239). Alternatively, a graphlet rooted in theaccess token (273) used in the activity (275), or a graphlet rooted inthe user identity (261) identified for the activity (275), or a graphletrooted in the device identity (277) corresponding to a match to theelectronic signature (187) for activity (275), can be extracted for thesubsequent analysis.

In FIG. 11, the controller (101) also receives (343) a list ofpredetermined user entities. The controller (101) is configured todetermine whether the user of the current request for access issufficiently connected to any of the list of predetermined entities. Todetermine the relation of the user of the current request and the listof predetermined user entities, the controller (101) extract (345), fromthe graph (239), a plurality of graphlets related to the user entitiesidentified in the list. For example, each of the extracted graphlets isrooted in one of the user entities in the list.

In FIG. 11, the controller (101) compares (339) first user entities inthe set of extracted element (e.g., the graphlet extracted for thecurrent activity (275), or the device entity (277) or the user identity(261) in the current activity (275)) to second user entities in thegraphlets extracted for the listed of predetermined user entities.

Based on a degree of similarity between the first and second userentities, the controller (101) approves, rejects or further investigates(341) the current request. For example, when a degree of similarity ofthe entities in the graphlet extracted for the current request (e.g.,rooted in the user identity (261) of the current request, or theactivity (275), or the token (273)) and the entities in the graphletextracted for a user identity in the predetermined list is above orbelow a threshold, the controller (101) rejects or approves the currentrequest.

The degree of similarity in entities in two graphlets can be measured invarious ways. For example, the degree of similarity can be configured tobe proportional to the count of entities common to the two graphlets.For example, the degree of similarity can be configured to beproportional to the count common connections between entities in the twographlets. For example, the degree of similarity can be a function of acount of common entities and common connections in the graphlets.

Other examples and details of the application of the technique thatcontrols access based on similarity in extracted graphlets can be foundin U.S. patent application Ser. No. 14/938,593, filed Nov. 11, 2015, theentire disclosure of which is hereby incorporated herein by reference.

FIG. 12 shows a method for authenticating a user entity for accesscontrol based on matching graphlets of a relation graph according to oneembodiment. For example, the method of FIG. 12 can be implemented in acontroller (101) of FIG. 4 in a system illustrated in FIG. 1; therelation graph can be constructed in a way as illustrate in FIGS. 6, 7and 8; and graphlets can be extracted for an activity in a way asillustrated in FIGS. 8 and 9.

In FIG. 12, the controller (101) is configured to receive (351) dataidentifying accesses made online, using access tokens (e.g., 141, 221, .. . , 223), from devices (122, 123, . . . , 125, . . . , 129) to accessresources in computer networks (e.g., 231, 233, 235). The received datamay include activity records (171, 225, 227, 229) of the accessactivities and/or contextual data associated with the activities, suchas device attributes (259) representing electronic signatures (187) ofthe respective devices (122, 123, . . . , 125, . . . , 129), and theuser attributes (251) containing user information (150).

The controller (101) organizes (353) the data in a graph form linkingelements including the access tokens (e.g., 141, 221, . . . , 223, 253,273, 283, 287, 289), user entities (e.g., 189, 241, 261, 281, 291),device entities (e.g., 185, 257, 277, 285), user attributes (e.g., 150,251, 271), device attributes (e.g., 187, 259, 279) based on theirconnections in the data, such as the relation graph (239) havingportions illustrated in FIGS. 7, 8, and 9.

In response to receiving (355) an identification of a user, thecontroller extracts (357), from the graph (239), a set of elementsconnected to the user up to a predetermined number of connections in thegraph (239).

For example, when the identification of the user matches with the useridentity (261) in the graph illustrated in FIG. 8, the controller (101)extracts a graphlet that is rooted at the user identify (261) and thathas elements connected up to a predetermined number of degrees ofseparation from the user identity (261) in the graph illustrated in FIG.8.

For example, when the identification of the user matches with the useridentity (261) in the graph illustrated in FIG. 8, the controller (101)extracts an initial graphlet rooted at the user identify (261) and thenextracts a resulting graphlet that elements have up to a predeterminednumber of degrees of separation from any of the elements in the initialgraphlet (or any of the elements of a predetermined type in the initialgraphlet).

In some instances, the resulting graphlet is extracted from a graph thatis separate from the graph from which the initial graphlet is extracted.For example, the graph from which the initial graphlet is extracted is abuilt based on a first set of activity records; and the graph from whichthe resulting graphlet is extracted is built based on a second set ofactivity records related to a set of blacklisted identities. Forexample, the graph from which the resulting graphlet is extracted can bea graph reduced from the graph from which the initial graphlet isextracted, where the reduced graph is obtained by replacing indirectconnections made via certain types of elements with direct connections(with indication of connection strength).

In FIG. 12, the controller (101) counts (359), in the set of extractedelements (e.g., a graphlet rooted at the user identity (261)),connections of the user to whitelisted user entities and connections ofthe user to blacklisted user entities. Based on the counts ofwhitelisted user entities and blacklisted user entities. the controller(101) authenticates (361) the user for access control.

For example, merchants and/or individuals involved with fraud typicallytry to create new identities rather quickly, to shake off known badreputations. By discovering connections or relationships, or evenmultiplicities of entities, locations, or other objects andrelationships or connections between new, apparently clean merchants,and existing ones, fraudulent activities on the merchants and/orindividuals can be detected early on.

Other examples and details of the application of the technique thatcontrols access based on the counts of connections to whitelisted userentities and/or blacklisted user entities can be found in U.S. patentapplication Ser. No. 14/949,305, filed Nov. 23, 2015, the entiredisclosure of which is hereby incorporated herein by reference.

In one embodiment, the growth rate of a cluster of attributes in arelation graph related to an access token (e.g., a user account) ismonitored for enhanced access control.

FIGS. 13 and 14 illustrate monitoring a growth rate of a cluster in arelation graph for access control according to one embodiment.

In FIG. 13, the attribute cluster (370) represents one of clusters ofelements in a relation graph (239) stored in a database of thecontroller (101) (e.g., in the form of a database for big data).

In FIG. 13, the cluster (370) of elements is centered at an access token(375) associated with the access context (381). The cluster (370)contains elements (371-383), which are exemplary elements for a typicalaccess token (e.g., a user account or a payment instrument). The actualnumber of elements may vary, depending on user activity, but they maytypically include elements such as the main access token (375), useraccess context (381), user name (373), IP addresses (376, . . . , 378)with corresponding device entities (377, . . . , 379) from whichaccesses have been made using the access token (375) via the context(381), addresses (374 and 371) (e.g., shipping addresses, paymentaccesses, and payment addresses), payment tools, and other elements(e.g., 372).

For example, when multiple devices having the device identities (377, .. . , 379) at different IP addresses (376, . . . , 378) are used to gainaccesses using the token (375), the size of the attribute cluster (370)grows.

In FIG. 13, the growth rate (383) tracks the rate of growth of thecluster (370). The controller (101) checks the cluster (370) todetermine how many new elements, such as device identity (379) and theIP address (378), are added to the cluster (370) and at what rate; andif the rate is suddenly accelerating, it is an indication of fraudstarting to happen. The controller (101) performs operations to controlaccess to prevent fraudulent accesses.

FIG. 14 illustrates the state of the attribute cluster (370) after itsgrowth following one or more access requests. In comparison with thestate of the attribute cluster (370) illustrated in FIG. 13, the stateof the attribute cluster (370) includes additional elements (e.g., 387,389) (e.g., after additional accesses are made using device (389) fromIP address (387) in a period of time. The addition of the elementschange the growth rate (385) of the attribute cluster (370).

In a typical scenario of ID theft or fraudulent use of an access token(e.g., an payment account), a person trying to take over the accesstoken performs activities that add to the attribute cluster (370)numerous devices (e.g., 379, . . . , 389) and IP addresses (378, . . . ,387) as part of the effort to take over the control of the access token,as well as, perhaps, some additional shipping addresses, all in veryquick succession. This rapid addition of elements causes the rate (385)of growth or change of the cluster (370) to increase dramatically. Thecontroller (101) monitors the change rate identified by the growth rate(385) of the cluster (370). A dramatic change/increase in the growthrate (385) can lead the controller (101) to flag the access token (375)for enhanced access control to delay and/or prevent fraudulent access.

There may be some legitimate situations, such as, for example, a personmoving two or three times in quick succession, perhaps first in atemporary location and then again in to a more permanent location, thatcause sudden growth in the change rate. In such cases, the controller(101) is configured to verify the changes, and in the meantime, atemporary hold may be imposed. In some instances, manual verification ofchanges are performed as a result of the growth rate (385) exceeding apredetermined threshold.

FIG. 15 shows a method for access control based on a growth rate of acluster in a relation graph according to one embodiment. For example,the method of FIG. 15 can be implemented in the system of FIG. 1 usingthe controller (101) of FIG. 4 based on the relation graph (239)illustrated in FIGS. 6-8. In some instances, the cluster is a graphletextracted from the relation graph (239) based on a particular rootelement of an interest, such as an access token, a user identity, adevice identity, an access context, such as electronic signature (187).

In FIG. 15, the controller (101) is configured to store (391) graph datalinking, in a graph form (e.g., relation graph (239)), elementsincluding access tokens, user entities, device entities, userattributes, device attributes based on their connections in the data. Inresponse to adding (393) an element (e.g., 389) to the graph identifiedby the graph data, the controller (101) identifies (395) a cluster(e.g., 370) of elements (e.g., 371-379, 381) in which cluster theelement is added. The cluster can be identified based on a statisticalanalysis of elements for a cluster of elements that are naturally closeto each other in the relation graph (239), or based on the extraction ofconnected elements up to a predetermined degree of separation from anelement of interest.

In response to addition of the element (389) to the cluster (370), thecontroller computes (397) a change rate or growth rate (385) of thecluster (370) and assesses (399) a risk of fraudulent activities in thecluster (370).

For example, the controller (101) can be configured to calculate andanalyze the rate of change of elements in a user account, according toone aspect of the system and method disclosed herein. When a new item(e.g., 389 or 387) is added to the database that stores the elementsrelated to the account of a user (e.g., 131), the addition of item(e.g., 389 or 387) causes the controller to recall/retrieve account datafrom the database (e.g., the attribute cluster (370) or a graphlet forthe user account). The controller (101) retrieves in particular dataabout additions of items with associated time stamps and calculates thechange rate of the data elements stored for the user account.

The change rate is calculated considering not only the total number ofitems stored in the database for the user account (e.g., the attributecluster (370)), but also factors such as how often and how recentlychanges have been made, and the type of changes.

In computing the change rate, changes of different types and/orattributes can be provided with different weights. For example, thecontroller (101) rates changes to elements such as payment accounts andshipping addresses more heavily than, for example, it rates elementssuch as IP address, because it is quite normal for a user to change IPaddresses often, but not necessarily shipping addresses. Accordingly,there is a whole range of additional factors entering into thecalculation of change rates, such as new devices, IP addresses, shippingaddresses, etc. that can indicate an onset of fraudulent access.

In some cases, for example including but not limited to, the addition ofnew payment and/or billing addresses could be an indicator of identitytheft. In some cases, for example including but not limited to, newdevices, IP or IP country, shipping addresses, phones, emails associatedwith an existing payment, etc. could be indication of payment fraud.Both sets need to be flagged and followed up with additionalinvestigations appropriate for the potential transgression.

The controller (101) compares the change rate to a preset limit orlimits. For example, the controller (101) may compare a single changerate that has weighted contribution from different types of dataelements to a single limit to detect a possible onset of fraudulentaccess. Alternatively or in combination, the controller (101) mayevaluate change rates corresponding to multiple facets of differenttypes of changes on shipping addresses, IP addresses, devices, etc.

If the change rate is above a threshold (e.g., based on a single changerate, the composite rate of the change rates for different aspects, orany of the change rates relative to a respective limit), the controller(101) is triggered to add other considerations for access control. Forexample, the controller (101) may further consider factors, includingbut not limited to, reputation of user, reputation of entities beingadded to the relation graph/graphlet of the user, transaction velocityfor entities involved, use of new or existing shipping address intransaction, absolute size of the user's graph, presence of other riskindicators within the transaction data (e.g., IP Geo-location to billingaddress distance, etc.). If, in view of the consideration of theadditional factors, the risk of the user account is still above a limit,the controller (101) flags the user account, possibly suspends/limitsfurther accesses/transactions within the user account until a review isperformed, manually or automatically, depending on the situation. Otheruser authentication and access control methods, such as the accesscontrol performed based on a trust score discussed in connection withFIG. 5, the access control performed based on matching elements of agraphlet against predetermined lists of elements as discussed inconnection with FIG. 10, the access control performed based on matchingelements of a graphlet against predetermined lists of elements asdiscussed in connection with FIG. 10, the access control performed basedon matching an extracted graphlet with graphlets extracted for a list ofpredetermined user entities as discussed in connection with FIG. 11, theaccess control performed based on counting connections in an graphlet towhitelisted and/or blacklisted user entities as discussed in connectionwith FIG. 12.

In one embodiment, the controller (101) is connected to an identityservice to provide enhanced user authentication and access control inconnection with and/or in combination with other user authentication andaccess control methods discussed herein.

FIG. 16 illustrates a system for user authentication using an identityservice according to one embodiment. For example, the system of FIG. 16can be implemented in a controller (101) of FIG. 4 in combination with asystem illustrated in FIG. 1.

In FIG. 16, an identity service (411) is configured to communicate witha user device (120) for identity protection. Based on a communicationfor registration (421), the identity service (411) stores data about auser (e.g., 131) of the user device (120) and provides the user device(120) with notices or alerts (429) of certain types of activities orevents. The registration data associates information about user devices(e.g., corresponding to device identity in a relation graph (239)) withrespective information about users of the user devices (e.g.,corresponding to the user identities in the relation graph (239)). Theidentity service (411) may maintain a limited device to user associationto facilitate push notifications to the user. The device to userassociation can also be obtained from the relation graph (239) via thecontroller (101).

Examples of such identity services are those offered for example but notexclusively by companies such as Experian, LifeLock and Equifax. Suchservices may be offered under many different brand names and withdifferent target audiences and pricing schema, sometimes sold directly,sometimes offered through re-sellers, but essentially offering some kindof credit and identity theft monitoring as part of the credit bureausbusiness models.

In FIG. 16, when the user device (120) accesses (423) the computing site(110), the access may trigger a fraud check for user authenticationand/or access control. For example, the user device (120) may access thecomputing site (110) using an access token to sign in the computing site(110), send a message to another user or make an exchange with anotheruser via the computing site (110), or make a payment transaction withthe merchant operating the computing site (110) using an account or apayment instrument.

The computing site (110) transmits to the controller (101) the details(425) related to the access that triggered the fraud check, such astransaction, email, payment, device, location, etc., as described aboveand throughout.

The controller (101) compiles into a relation graph (239) the dataspecifying the details (e.g., 425) associated with various accesses madeby various user devices (e.g., 120) using access tokens (e.g., 141). Therelation graph can be constructed in a way as illustrate in FIGS. 6, 7and 8.

When the user device (120) uses the access token (403) to access (423)the computing site (110), the controller (101) mergers the details (425)received from the access (423) into the relation graph (239) and/orextract a graphlet based on the identification of the user identity(401) determined for the access (423), the device entity (407)determined for the access (423), or the access token (403) used in theaccess (423). The graphlet can be extracted in a way as illustrated inFIGS. 8 and 9.

In response to a determination that the details (425) add new elementsand/or connections to the relation graph (239), the controller (101)reaches out via a query (427) to the identity service (411) (e.g., an IDprotection service or an ID fraud protection services). Only one service(411) is shown in FIG. 16, for clarity and simplicity, but in general,more than one identity service can be used in the system in connectionwith the controller (101). The query (427) is configured for aconfirmation of new details (425) in the access (423) being examined(e.g., an online activity, a login session, a transaction, messaging,trading).

Based on the registration data stored in the identity service (411), theidentity service (411) provides the controller (101) with a validation(431) of the information provided in the query (427), which confirms oneor more relations among data elements in the relation graph (239).Alternatively or in combination, the identity service (411) provides theinformation about user to device association to the controller (101) atthe registration time to incorporate the association in the relationgraph (239) and enable the validation to be performed by the controller(101) directly; and if the controller (101) identifies an element thatis new to the relation graph (239), the query (427) causes the identityservice (411) to generate an alert (429) to the user device (120) (sincethe identity service (411) typically has less information than thecontroller (101)). It is not required that the identity service (411)maintain its own set of associations.

For example, the validation (431) may indicates the ownership of anelement (e.g., a device identity (409) of the device (120)) by a useridentity (401), which causes the controller (239) to add to the portionof the graph (239) for the user the connection between the element(e.g., the device identity (409)) and the user identity (401). If thedevice identity (409) is known to the identity service (411) and/orassociated with the user identity (401), the identity service (411) maynot send an alert (429) to the registered user device (120). If thedevice identity (409) and/or its connection to the user identity (401)is new to the identity service (411), the identity service (411)provides an alert (429) to the user device (120) registered forassociation with the user identity (401) and/or to the controller (101).

In some cases, the access would be placed on hold until the user (e.g.,131) has confirmed the new details as being legitimate via the identityservice (411) and/or the controller (101). For example, in response tothe alert (429), the user (e.g., 131) may use the user device (120) torespond to the identity service (411), confirming the association of thedevice identity (409) corresponding to the user device (120) and theuser identity (401) corresponding to the user (e.g., 131) who is usingthe access token (403). If the user (e.g., 131) confirms the device(120) to the identity service (411) as a legitimate device of the user(e.g., 131), the identity service (411) confirms the association to thecontroller (101) via the validation (431), and no further action isvisible to the user (e.g., 131). Knowledge of the device (120) is addedto the graph (239) in the form of elements (e.g., device identity (409)connected to the user identity (401)). The elements stored in therelation graph (239) according to the validation (431) may includevalidation details, such as the identification of the source ofconfirmation (e.g., an identifier of the identity service (411) thatprovides the validation (431)), the time/date stamp of the validation(431), and an confirmation ID, etc. The validation details can be storedas part of the element of the device identity (409) and/or itsconnection to the user identity (401) for future use as a legitimatedevice (120) of the user (131) using the access token (403).

FIGS. 17 and 18 show methods for user authentication using an identityservice according to one embodiment. For example, the methods of FIGS.17 and 18 can be implemented using a system illustrated in FIG. 16.

In FIG. 17, a controller (101) is configured to authenticate a user inresponse to receiving (441) (e.g., from a computing site (110)) detailsof an access request (e.g., an access (423) made using an access token(403) on a user device (120)). For example, the access token (403) isassociated in the relation graph (239) with the user identity (401); andbased on the details (425), the controller (401) identifies the useridentity (401) as a representation of the user who is making the access(423) using the device identity (409) representing the user device(120). When the details (425) of the access (423) creates a newconnection between the device identity (409) and the user identity (401)in the relation graph (239), the new connection adds the device identity(409) as a new element to a graphlet rooted in the user identity (401)(or the access token (403)). For example, in response to the details(425) of the access (423), the controller (101) extracts a graphletrelated to the access (423) (e.g., using the methods discussed inconnection with FIGS. 8 and 9) and determine if any new elements isadded in the graphlet by the details (425) of the access (423).

In FIG. 17, the controller (101) retrieves (443) from a relation graph(239) a set of elements based on the details (425) of the access (423)and determines (445) whether an element is new to the retrieved set ofelements (e.g., being added to the set in view of the details (425) ofthe access (423)).

In FIG. 17, if an element is new, the controller (101) determineswhether the user (e.g., as being represented by the user identity (401)in the retrieved set of elements)) is connected to an identity service(e.g., 411)). If the user determined (447) to be connected to anidentity service (411), the controller (101) sends (451) a request tothe identity service (411) that causes the identity service (411) tovalidate, against its stored registration data (if the identity service(411) maintains such registration data), a relation between the newlyadded element and the user (e.g., as being represented by the useridentity (401) in the retrieved set of elements)). After the controller(101) receives (453) a response from the identity service (411), thecontroller determines (455) whether the response is positive (e.g.,whether the association between the newly added element and the useridentity (401) representing the user is confirmed via the registrationdata stored in the identity service (411), if such data exists). If theresponse is not positive (455), the controller (101) communicates withthe computing site (110) to reject (457) the access request.

If the controller (101) determines (447) that the user is not connectedto an identity service, the controller (101) may perform (449) optionalverification operations for the association between the new element andthe user.

In FIG. 17, the controller (101) performs (459) a standard verification(e.g., any of the other user authentication and/or access control methoddisclosed herein or another method known in the field), if noassociation of the elements with the user represents a risk offraudulent access.

For example, the user authentication technique of FIG. 17 can be appliedto fraud prevention in the use of a payment account. When a user startswith a new transaction with a merchant using a payment account, a newfraud check request comes in to the controller (101). The computersystem of the merchant (e.g., the computing site (110)) sends thetransaction details to the controller (101), which adds the details toits database and retrieves from the database matching key identityelements that form the relation graph (239) (or a graphlet extracted forthe transaction, the user, and/or the payment account). The database ofthe controller (101) can be a classic database or a big data database.The controller (101) checks to determine if the transaction presents anynew elements, such as a new device, or anything else that is hithertounknown, or known but not previously associated with the other dataelements of the transaction or any of the entities involved. If thetransaction adds no new element to the retrieved set of elements, thecontroller (101) proceeds with a standard verification. If everythingchecks out OK, the controller (101) confirms the user authentication forthe transaction and sends a confirmation response (433) to the computersystem of the merchant (e.g., computing site (110)). If the controller(101) cannot confirm the transaction, the controller may send an abortmessage to the computer system of the merchant.

If the controller (101) identifies one or more new elements that areadded to the retrieved set of elements by the transaction, thecontroller (101) checks to determine whether the identification of theuser has any connection to a known identity protection service; and ifso, the controller (101) contacts the corresponding identity protectionservice (e.g., 411) and sends a request to the identity protectionservice for confirmation of any new element(s) of the user, such as, forexample, a new device (120). Although only one exemplary identityservice (411) is shown in FIG. 16, for clarity and simplicity, there maybe a multitude of different services. Other requests, in addition torequests for confirmation of new devices, may include, but are notlimited to, confirming new addresses, new payment accounts, emails,phone numbers, ESNs, IMEIs, SSN, TINs, SIM, etc. as well as confirmingtransactions that are above a certain amount threshold, confirming moneytransfers that are going to foreign countries, or countries with whichthe user has not previously transacted with or otherwise suspect.

The identity protection service (e.g., 411) may have its owncomputer-implemented procedures, such as communication with the user atthe user device (120) (or another device) directly or via email, SMS,automated phone call, etc. The user may expect some interaction with theidentity protection service but may not expect to be contacted by amerchant fraud protection service. Once the identity protection servicecompletes it identity verification (e.g., based on its registration dataand/or communication with the user), it responds back to the controller(101) via a communication channel for the validation (431). In response,the controller (101) checks to determine whether the response ispositive, that is, the user data can be verified. If not, the controller(101) goes into the abort procedure, sending an abort message to thecomputer system of the merchant over a communication connection. If theresponse is positive, the controller (101) moves to the standardverification procedure.

In FIG. 18, the controller (101) is configured to: store (461) data in agraph form linking elements including the access tokens, user entities,device entities, user attributes, device attributes based on theirconnections in the data; receive (463) details (425) of a request foraccess (423); determine (465) a user identity (401) of the request and adevice identity (409) of the request from the details (425) and thegraph (239); identify (467) a new connection, introduced by the requestfor access (423), between the user identity (401) and the deviceidentity (409) in the graph (239); communicate (469) with an identityservice (411) to determine a risk associated with addition of the newconnection in the graph (239); and accept, (471) rejection, or furtherinvestigate the request based on the risk.

In one embodiment, the controller (101) for user authentication andaccess control includes: at least one microprocessor (145); memory (160)coupled with the at least one microprocessor (145); and a networkinterface (143) controlled by the at least one microprocessor (145) tocommunicate over a computer network (100) with: at least one computingsite (110), and at least one identity service (411). The identityservice (411) is a computing facility that can be implemented using oneor more computers. The identity service (411) stores identificationinformation of a user (e.g., 131) and is configured to communicate witha registered device (e.g., 120) of the user for identity protection.

The memory (160) of the controller (101) stores graph data representinga graph having: nodes representing data elements associated withaccesses made using an access token (403), and links among the nodesrepresenting connections between the data elements identified in detaildata of the accesses, such as a graph (239) illustrated in FIG. 16.

The memory (160) of the controller (101) stores instructions which, whenexecuted by the at least one microprocessor (145), cause the controller(101) to: receive, from the computing site (110), input data specifyingdetails (425) of an access (423) made using the access token (403); anddetermine, from the input data: a device identity (409) representing auser device (120) from which the access (423) is made using the accesstoken (403), and a user identity (401) representing the user (e.g., 131)who the access token (403) to make the access (423) from the user device(120).

The controller (101) updates the graph (239) according to the inputdata, identifies, in the graph (239), a new connection resulting fromupdating the graph (239) according to the input data, and transmits aquery (427) over the network (100) to the identity service (411). Thequery (427) causes the identity service (411) to verify association ofdata elements corresponding to the new connection identified in thegraph (239).

After receiving, over the network (100) and from the identity service(411), a validation (431) responsive to the query (427), the controllerprocesses the access (423), made using the access token (403), based onthe validation received from the identity service (411).

For example, in response to the query (427), the identity service (411)determines whether the association of the data elements corresponding tothe new connection identified in the graph (239) is confirmed by theidentification information stored in the identity service (411) (e.g.,stored as part of a registration (421) and/or subsequentcommunications). In response to a determination that the association ofthe data elements cannot be confirmed by the identification information(e.g., registration data), the identity service (411) transmits an alert(429) to the registered device (e.g., 120) of the user or to the user'sregistered email or SMS to a registered phone, etc.; and the validation(431) is transmitted from the identity service (411) to the controller(101) in response to a reply to the alert (429). The reply may includedata of registration (421) to confirm the association, or a rejection ofthe association (e.g., when the access is fraudulent).

In response to a determination that the identity service (411) cannotconfirm the association of the data elements corresponding to the newconnection identified in the graph (239) (e.g., even after the alert(429) and its associated reply or, in some instances, without waitingfor the reply to the alert (429)), the controller (101) communicateswith the computing site (423) to block the access (423) in somesituations.

An example of the new connection identified in the graph is a newconnection between a node representing the device identity (409) and anode representing the user identity (401). Another example of the newconnection identified in the graph is a new connection between a noderepresenting the device identity (409) and the node representing theaccess token (403). The association of the data elements correspondingto the new connection identified in the graph to be confirmed by theidentity service (411) may include the association of attributes of thedevice identity (409) and the user identity (401), the association ofattributes of the device identity (409) and the access token (403),and/or the association of attributes of the access token (403) and theuser identity (401)

The user identity (401) can be determined according to the input databased on its previous establish connection to the access token (403)used to make the access (423), some of the attributes of the deviceidentity (409), and/or other data. In some instances, the controller(101) determines the user identity (401) based on an electronicsignature (187) generated from the input data received from thecomputing site (110) for the user authentication and/or for the controlof the access (423).

In some instances, when the association of the data elementscorresponding to the new connection identified in the graph cannot beconfirmed, the controller (101) flags the user identity (401) as animposter candidate (e.g., for further analysis and/or future analysis ofother access instances).

The graph (239) can be identified for the update based on the accesstoken (403), the identified user identity (401) of the access (423),and/or the identified device identity (409) of the access. In someinstances, the graph is generated based on a cluster of accessactivities after a cluster analysis is performed to identify the clusterfrom a large set of access activities. In some instances, the graph(239) is extracted from a larger graph generated from a large set ofaccess activities, wherein the extraction is based on a node of interestselected according to the input data and a predetermined number ofdegrees of separation from the selected node (and/or other criteria).

In some instances, the controller (101) identifies the identity service(411) based on the user identity (401), the device identity (409),and/or the access token (403).

The controller (101) may optionally determine from the graph data ascore representing a risk of the access being fraudulent and processesthe access (423) made using the access token (403) based on the score.

In some instances, it is desirable to prevent certain users identifiedin a list and/or users who are in close relation with the users on thelist from certain types of accesses.

For example, a list of persons may be identified as officiallysuspected, sanctioned or politically exposed persons (PEPs). Persons inrelationships (PIRs) with the PEPs, as well as the PEPs, may have accessrestrictions. However, some of the persons may attempt to defeat therestriction by making fraudulent accesses.

In one embodiment, the controller (101) is configured to perform acluster analysis of the data relating to the veracity and/or reality ofPIRs for access control. If the controller (101) analyzes sanctioninformation elements and detects introduction of new, suspicious or fakePIRs as a means of circumventing sanction screening, such a suspiciousPIR then may be flagged for further investigation and/or access control.A flagged PIR cluster can be further reviewed, even if only one PIRwithin was originally flagged, and, based on a hit with a suspectentity, the breadth of the examined co-related items may be expanded byan additional number (e.g., by increasing the degrees of separate usedto extract the items of a graphlet from a relation graph), and if thatexpansion results in exposure of one or more suspicious connections, afurther expansion may increase the degree of relationships examined. Thesearch of such information for the relation graph is not limited to thepublic Internet per se, but could include any and all accessible sourcesof data, including but not limited to other data bases, public or not,such as government databases, some publicly accessible privatedatabases, credit reporting systems, dark web (for example, see web pageat en.wikipedia.org/wiki/Dark_web), person information and registrationsystems, sanctioned persons systems, etc.

In some situations, officially suspected, sanctioned or politicallyexposed persons (PEPs) may resort to using fake identities to transactand receive payoffs, in order to hide the true aspect of the events. Thecontroller (101) of one embodiment is configured to detect the use ofsuch techniques or at least to flag the possible use of them, for fastand easy investigations.

In sanction screening, the controller (101) is configured to compare theuser identities of individuals and business entities against availablelists representing regulatory sanctions. Regulations governing detailedreviews, particularly reviews of financial situations and transactionsmay, in the cases of a truthful (accurate) match against such lists,prevent a regulated entity (typically a person or institution reviewingor asked to review a proposed transaction) from further analyzing aproposed transaction, and in some cases stop said proposed transaction.

In the present application, a transaction generally involves access topredetermined resources and does not necessarily include movement ofmoney. For example, a “proposed transaction” can be an onboardingprocess (or a third-party review during such a process), say, forissuing a loan or a lease to an apartment, or opening some other kind ofaccount or process. Not all lists that are part of sanctions implydenying accesses or services. In some instances, lists containing, forexample, names of officially suspected, sanctioned or politicallyexposed persons (PEPs) imply that the reviewing entity needs to performenhanced due diligence (EDD) on the individual or the business. But suchEDD doesn't mean that the access must be denied.

FIG. 19 shows an example of a network of related identities of oneembodiment.

In the example of FIG. 19, the network of related user identities isrooted at a person named John (501) who is on a list of politicallyexposed persons (PEP). The network of related user identities can beextracted from a relation graph (239) using a technique discussed inconnection with FIGS. 6-9. In some instances, the network of relateduser identities is identified based at least in part on a socialnetworking site. In other instances, the network of related useridentities is identified without using a social networking site.

In the example of FIG. 19, John (501) is connected to, for example, Jack(502), who is further connected to, for example, Tom (504), and Joe(503). Thus, the connected persons in the network can be considered asfriends of John (501).

In a scenario, upon investigation, Tom (504) is shown to be a fakeidentity. Because Tom (504) is a fake identity, further investigation iscalled for, and it turns out that Dick (505) is also a fake identity,and all the names related to Dick in his network (506) are also fakeidentities. The discovery of these fake identities raises the suspicionthat those people may have been used, for example, to launder money, orprovide favors, or both, sent to John, and those activities have beenused to hide real benefits that were given to John without declaringthem properly.

FIG. 20 shows a method of user authentication based on a network ofidentities according to one embodiment. For example, the method of FIG.20 can be implemented in a controller (101) of FIG. 4 in a system ofFIG. 1 using a relation graph (239) of FIG. 6 or FIG. 19.

In FIG. 20, the controller (101) is configured to investigate a networkof identities, such as the network illustrated in FIG. 19. The detecting(511) of a change in the relationships illustrated in FIG. 19 causes thecontroller (101) to activate the investigation.

Typically, such a triggering change could include adding or removingnetwork members, or a change in status of a person close to the personon the predetermined list (e.g., PEP John 501), such as the change ofstatus of a person who is connected to the listed person (e.g., 501)with one or two degrees of separation in the network (e.g., having afirst or second relationship to the PEP).

In FIG. 20, the controller (101) identifies an identity of an graph of anetwork original network (e.g., the user identity of John (501)) andretrieves (515), from the data storage unit of the controller (101), thenetwork data identifying the network of user entities. Based on recentaccess activities, the controller (101) creates (517) a list of changesin the network.

For each of the changes, the controller (101) scans (519) in the networkup to a predetermined number of degrees of separations. In the relationgraph or user entity network as illustrated in FIG. 19, two persons areconsidered to have “n” degrees of separate when the minimum path betweenthe two persons in the network has “n” direct connections. A scan of tothe “n” degrees of separate identifies the user identities that areconnected from a changed user identity not more than “n” degrees ofseparation; and the controller (101) identifies (521), in the scannedpart of the network, user identities that are fake or suspicious.Suspicious or fake identities are flagged for follow-up

The “n” can be modified to a greater or lesser degree, depending onjurisdiction, laws, the status of the PEP, and also whether problemshave been previously identified with this network of user identities.

In FIG. 20, the controller (101) determines (523), based on a result ofidentifying the fake or suspicious entities in the network, determineswhether any identities require action by some authority; and if so, thecontroller (101) sends (525) a notification to a predetermined person(s)or agency.

For example, the controller (101) collects sanction-related informationfrom sources related to persons (or entities, as in juristic persons) inrelationships (PIRs) with officially suspected, sanctioned orpolitically exposed persons (PEPs). The controller (101) performs acluster analysis of additional data about the veracity and/or reality ofPIRs. Thus, suspect persons and or other entities in the environmentaround PEPs (e.g., within a predetermined number of degrees ofseparation from the PEPs in a network of user identities) can be foundand if necessary flagged for further examination. Further, if thecontroller (101) detects introduction of new, suspicious or fake PIRs asa means of circumventing sanction screening, such a suspicious PIR thenmay be flagged for further investigation. If any PIR in a cluster isflagged, the whole PIR cluster can be further reviewed, even if only onePIR within was originally flagged; and, based on a hit with a suspectentity, the breadth of the examined co-related items may be expanded byan additional number (e.g., the number of degrees of separate used toidentified the environment can be increase for cluster expansion), andif that expansion results in exposure of one or more suspiciousconnections, a further expansion may increase the degree ofrelationships examined. The search of such information is not limited tothe public Internet per se, but would include any and all accessiblesources of data, including but not limited to other data bases, publicor not, such as government databases, some publicly accessible privatedatabases, credit reporting systems, dark web or similar (for example,see web page at en.wikipedia.org/wiki/Dark_web), person information andregistration systems, officially suspected persons, sanctioned personssystems, etc.

FIG. 21 shows a method to control access based on a network ofidentities according to one embodiment. For example, the method of FIG.20 can be implemented in a controller (101) of FIG. 4 in a system ofFIG. 1 using a relation graph (239) of FIG. 6 or FIG. 19.

In FIG. 21, the controller (101) is configured to store (531) graph datarepresenting a graph having: nodes representing data elements identifiedin input data about accesses made using access tokens on user devices;and links connecting the nodes. In response to receiving (533) inputdata specifying details (425) of an access (423) made using an accesstoken (403), the controller (101) identifies (535) changes to the graph(239), where the changes result from the updating of the graph (239)according to the input data.

For a given respective change, the controller (101) identifies (537) aset of elements corresponding to nodes in the graph (239) that are up toa number of degrees of separate from the respective change and evaluates(539) trustworthiness of first user identities corresponding to thefirst set of elements. for example, the controller (101) may reduce thegraph (239) to a graph containing only user identities by replacingdirect connections provided by other types of nodes with directionconnections. Alternatively, the controller (101) may treat each nodethat is not a user identity as a part of a connection between useridentities.

In FIG. 21, the controller (101) determines (541) whether the useridentities identified from the change are trustworthy. For example, thecontroller (101) may change whether any of the user identities are on alist of fake user identities and/or suspicious user identities. Forexample, the controller (101) may count those of the user identitiesthat are on a list of fake user identities and/or suspicious useridentities and determine if the count is about a threshold.

If the user identities identified from the change are not trustworthybased on a predetermined criteria, the controller (101) increases (543)the number of degrees of separation to identify an expanded set ofelements in a way similar to the operation (537) discussed above. Thecontroller (101) then evaluates (545) trustworthiness of second useridentities identified according to the increased number of degrees ofseparation.

When the trustworthiness of second user identities do not meet arequirement, the controller (101) may further increase (543) the numberof degrees of separate for identifying related user identities, orreject, block, and/or flag the current access, the access token used inthe current access, and/or the user identity for the user making thecurrent access.

In some instances, the controller (101) also performs other checks, suchas the growth rate (383), the trust score as discussed in FIG. 5, and/orquery (427)/validation (431) with an identity service (411) of FIG. 16.

In one embodiment, the controller (101) for user authentication andaccess control has: at least one microprocessor (145); a networkinterface (143) controlled by the at least one microprocessor tocommunicate over a computer network (101) with at least one computingsite (110); and memory (160) coupled with the at least onemicroprocessor (145) and storing graph data representing a graph having:nodes representing data elements associated with accesses made usingaccess tokens, and links among the nodes representing connectionsbetween the data elements identified in collected data about theaccesses. The memory (160) further stores instructions which, whenexecuted by the at least one microprocessor (145), cause the controllerto: receive, from the computing site (1010, input data specifyingdetails (425) of an access (423) made using an access token (403);update the graph (239) according to the input data; and identify changesin the graph (239) resulting from updating the graph according to theinput data.

For each respective change among the changes resulting from the updatingof the graph, the controller (101) identifies a first set of elementscorresponding to nodes in the graph that are up to a first predeterminednumber of degrees of separation from the respective change and evaluatestrustworthiness of first user identities corresponding to the first setof elements to process the access (423) made using the access token(403) based on the trustworthiness of the first user identitiescorresponding to the first set of elements.

For example, the trustworthiness of the first user identities can beevaluated by comparing the first user identities to a list to determinewhether any of the first user identities is on the list; and in responseto a determination that at least one of the first user identities is onthe list, the controller further identifies a second set of elementscorresponding to nodes in the graph that are up to a secondpredetermined number of degrees of separation from the respectivechange. The second predetermined number of degrees of separation islarger than the first predetermined number of degrees of separation, andthe second set of elements does not include any of the first set ofelements. The controller (101) evaluates trustworthiness of second useridentities corresponding to the second set of elements and processes theaccess made using the access token based at least in part on thetrustworthiness of the second user identities corresponding to thesecond set of elements.

For example, the first user identities may be considered untrustworthywhen one of the first user identities is on a list of fake useridentities or a list of suspicious user identities.

For example, the first user identities may be considered untrustworthywhen a count of user identities matching a sanction or PEP list is abovea threshold.

In response to a determination that the trustworthiness of the firstuser identities does not meet a predetermined requirement, thecontroller (101) may: identify a second set of elements corresponding tonodes in the graph that are up to a second predetermined number ofdegrees of separation from the respective change, where the secondpredetermined number of degrees of separation is larger than the firstpredetermined number of degrees of separation; evaluate trustworthinessof second user identities corresponding to the second set of elements;and process the access made using the access token based at least inpart on the trustworthiness of the second user identities correspondingto the second set of elements.

Based on the trustworthiness of the second user identities, thecontroller (101) may communicate with the computing site (110) to blockthe access (e.g., in response to a determination that a count of asubset of the second user identifies that fake and/or suspicious isabove a threshold)

The graph (239) can be identified for the update based on the accesstoken (403), the identified user identity (401) of the access (423),and/or the identified device identity (409) of the access. In someinstances, the graph (239) is generated based on a cluster of accessactivities after a cluster analysis is performed to identify the clusterfrom a large set of access activities. In some instances, the graph(239) is extracted from a larger graph generated from a large set ofaccess activities, wherein the extraction is based on a node of interestselected according to the input data and a predetermined number ofdegrees of separation from the selected node (and/or other criteria).

The controller (101) may optionally determine from the graph data ascore representing a risk of the access being fraudulent and processesthe access (423) made using the access token (403) based on the score.

For example, the controller (101) of one embodiment is configured toperform computerized fraud detection. After collecting contextualinformation and fraud information and analyzing new elements in atransaction request submitted from a merchant, the controller (101)identifies data related to any new element introduced by the transactorand contacts one or more ID fraud protection services to confirm thevalidity of the new element, such as the device of the transactor, thepayment account used in the transaction, the shipping address requestedfor the transaction, the billing address identified for the transaction,an email address identified for the transaction, a phone numberidentified for the transaction, a national ID of the transactor, etc.Upon receiving a confirmation from an ID fraud protection service, thecontroller (101) adds the element to the transactor profile in thesystem. The ID fraud protection service may also notify the transactorof a new device never used before on his/her/its account; and additionalqueries from the fraud detection system may be passed through the IDfraud protection service to the transactor through its trustedcommunication channel.

In one embodiment, the controller (101) is configured to insert dataelements in a relation graph configured to track the relations ofelements observed in certain computerized accesses made using one ormore access tokens. When a new element is inserted into the graph, thecontroller (101) computes a risk score based on a plurality ofmeasurements of the graph. In response to the risk score being above athreshold, the controller (101) performs further operations toauthenticate users and/or control access to prevent fraudulent access.Another example is the use of the risk score in the positive sense: ifthe score is below a second threshold then this can be taken as a strongindicator that the transaction is low risk and no further analysis isrequired.

FIG. 22 illustrates an example of a graph of data elements related toaccess activities according to one embodiment. For example, the graph ofFIG. 22 can be generated based on activity records (225, 227, 229)collected from one or more of the networks (231, 233, 235) illustratedin FIG. 6. The collected information in the activity records (225, 227,229) includes the identification of activities, the parameters of theactivities, and the contextual information of the activities, such asthe information of devices used to perform the activities, the networkconfiguration of the devices at the time of the activities, etc.

The graph illustrated in FIG. 22 includes elements and connectionslinking the elements based on the observed relations of the elements inthe activity records. Examples of types of elements illustrated in FIG.22 includes activities, users (e.g., represented by user identities),devices (e.g., represented by device identities), user addresses, IPaddresses, etc. In general, a relation graph (239) may also includeother types of elements, such as access tokens, device attributes, userattributes, etc.

In FIG. 23, the nodes identifying the elements of the graph include dataindicative the quality of the information about the respective nodes,such as good, bad, unknown, very good, suspicious, etc.

In some instances, the links identifying the connections betweenelements of the graphs may optionally include additional informationabout the respective connections. For example, the link (561) betweenthe nodes (e.g., 551 and 552) may include information indicating whetherthe link is bidirectional during an activity (e.g., a transaction)and/or the direction of the connection. Sometimes a set of informationconnects to another set both ways during an activity; and sometimes thetwo sets connect in only one direction. Links going in only onedirection indicates that one set of information is derived from anotherset, or one set is linked to a different set during an activity but onlyin one direction.

For example, if a payment method is attached to a transaction and apayment address is included/used for the transaction, the associationbetween the payment address and the payment method is considered strongas a result of the transaction, but the association between the IPaddress used to conduct the transaction and the payment method is notconsidered strong as a result of the transaction. Thus, the transactionand the IP address may be linked in the graph with a bidirectionalconnection, but the IP address and the payment method may be onlyloosely linked, therefore the link between the IP address and thepayment method may not be bidirectional.

The information about the link directionality, whether bidirectional orone-way only, can be used subsequently for user authentication and/oraccess control, e.g., when a lookup is done to determine whether an IPaddress is linked to a payment method.

In some instances, the graph also stores information indicating thestrength of a link/connection between two nodes/elements connected bythe link/connection. The strength indicator can be derived from one ormore activity records (e.g., for repeated observations of the relationin multiple activities).

For example, if an IP address is used for a fraudulent transaction, theinformation may indicate whether this payment was from that certain IPaddress or not.

The design and implementation of the tracking and recording of suchinformation for the graph is further discussed below in greater detail.

In one embodiment, the graph as illustrated in FIG. 23 is a graphletextracted from a large relation graph (239) (e.g., extracted using atechnique as discussed in connection with FIGS. 8 and 9). In anotherembodiment, the graph is identified via a statistical cluster analysisof elements, activities, and/or transactions; and constructed from theitems in a cluster identified from the statistical cluster. In a furtherembodiment, the graph is generated by incrementally adding relatedhaving connections to the existing elements in the graph when moreactivity records become available over a period of time. Certainrestrictions may be used to limit or regulate the growth of the graph.For example, the graph may be limited by a maximum allowed number ofdegrees of separate from a newly added element to one or more keyelements of interest for the graph.

For example, the metrics tracked and recorded for a graph may include:total entities that are attached to a person; total entities of aspecific type that are attached to the person; total entities having aspecific reputation that are attached to the person; and total entitiesof a specific type and having a specific reputation that are attached tothe person.

For example, the metrics tracked and recorded for a graph may furtherinclude: total recent new entities that are attached to the person;total recent new entities of a specific type that are attached to thepersons; total recent new entities having a specific reputation that areattached to the person; and total recent new entities of a specific typeand having a specific reputation that are attached to the person.

In one embodiment, a recent time period is a 7-day period from thepresent time (or the time of the update of the metrics. The length ofthe recent time period can be contextually adapted to the circumstances.For example, in a very fast-paced transaction environment of onlinegaming, a recent time period may be shortened to the last 2 hours;online merchandise delivery, the recent time period can be the last week(e.g., “7 days”).

For example, the metrics tracked and recorded for a graph may furtherinclude: total entities that are attached to a merchant; total entitiesof a specific type that are attached to the merchant; total entitieshaving a specific reputation that are attached to the merchant; andtotal entities of a specific type and having a specific reputation thatare attached to the merchant.

Other metrics may include, for example, total blacklisted entities inthe graph, total counts of activities having undesirable results (e.g.,chargeback and fraudulent refund), and a previous graph score.

In one embodiment, a score is computed for a graph/graphlet to indicatethe risk of a transaction with entities contained within the graph. Thecalculation of the score takes into account various facets of the graph,by assigning different weights to each of the items measuring the facetsof the graph. The weights can be tuned based on historic events and thusresults in an artificial intelligence type of learning capability of thecontroller (101).

Example items measuring the facets of the graph include:

the total number of entities in the graph;

the reputation of the entities in the graph;

the growth rate of the graph;

the number of new entities added to the graph in a predetermined recentperiod (e.g., the last 7 days for online merchandise delivery, the last2 hours for online gaming);

the breadth of the graph (e.g., the maximum degrees of separationsbetween elements/nodes in the graph);

the depth of the graph (e.g., the maximum degrees of separations fromone or more key elements of the graph to other elements in the graph);

the number of entities in the graph that are each blacklist;

the number of entities in the graph that are each sanctioned or membersof sanction lists; and

the number of entities in the graph that have a specific category tag(e.g., drop shipper, fraud ring, identity theft).

Scoring, for example, uses a system of weighting of each of theaspect/faucet items. The controller uses the score of the graph/graphletto produce a risk assessment for elements in the graph and/or controlaccess and/or authenticate users based on the risk.

Some of the aspects can be industry specific type parameters, that arerelevant only in one industry, but not in another. Typically, that wouldentail some or all of the items in the merchant category/subcategoriesand the resulting values/tags.

The weights and formula for the graph score can be tweaked to reduce theimpact of criteria and/or parameters/facet items that are not asrelevant for a specific use. For example, having a sanctioned entitywithin the graph but not a direct participant in a transaction may notbe a concern of an anti-fraud operation in payment transactions. Thus,the score of the graph can be customized for various specific uses, suchas customer onboarding, payment transaction anti-fraud, anti moneylaundering, sanctions screening, etc.

FIG. 23 shows a method of user authentication based on adding an elementto a relation graph according to one embodiment. For example, the methodof FIG. 23 can be implemented in a controller (101) of FIG. 4 in asystem of FIG. 1 using a relation graph (239) of FIG. 6 and/or FIG. 22.

In FIG. 23, the controller (101) adds (571) a new item to a relationgraph (239) in response to an incoming call, such as a transmission ofthe details (425) of an access (423) made by a user (e.g., 131) of adevice (120) using an access token (403) illustrated in FIG. 16.

The graph (239) and the relevant data are stored in the data store ofthe controller (101). The data store may be a local store, or acloud-based store. The data store may be in one location or distributedacross a plurality of devices connected over a network, or anycombination thereof.

In FIG. 23, the controller (101) determines (573) the new data item fitswith the current schema of the graph (239); and if not, the controller(101) dynamically modify (575) the schema of graph to accommodate theinsertion of the new item.

For example, the controller (101) of one embodiment modifies thestatistical boundaries of the graph to accommodate the insertion of theinsertion of the new item. In some cases, certain preset boundaries maybe statistically adapted and dynamically modified, based on calculationsof averages, etc. As each access activity (e.g., transaction) is addedto the graph, some boundaries may be slightly moved, due to shiftingupper and lower boundaries and shifting averages. Such modifications maybe done on a per transaction basis or by periodic recalculation (daily,weekly, monthly, etc.). In some other cases, an analysis modification isperformed to create additional statistical boundary information, soadditional information and data and/or meta data and their subsetscontaining relevant information about newly added information may beadded for storage in both nodes/elements and vectors/links/connectionsconnecting the nodes/elements in the graph. After the modification, thecontroller (101) verifies (577) the modifications for data storage. Uponcompletion of the modification, the controller (101) logs (579) apedigree in the form of a record indicating what has changed, and when,why, and how. The predigree can be logged and stored into the data storeof the controller (101).

When the graph scheme can accommodate the insertion of the new item, thecontroller (101) creates (571) a new node for the new item and populatesthe new node with data received from a network (e.g., 231, 233, 235)regarding the new item. The network may be a private network (e.g., atransaction network, a merchant network, a banking network, a financialnetwork, etc.), or a public network, or a combination of public andprivate networks. Some information may also be retrieved from data storeof the controller.

The controller (101) stores (585) the result of the new node having thepopulated data in the graph back into the data store of the controller(and also in other places as appropriate).

In FIG. 23, the controller (101) calculates (587) a score of the graphand determines (589) where the score it exceeds a predeterminedthreshold.

If the graph score exceeds the threshold, the controller (591) performs(591) additional and/or optional checks for user authentication andcontrols (593) user access as a result. For example, the controller(101) may block the access (423) associated with the new item, set aflag for the graph and/or selected elements in the graph, and/or notifya relevant computing system (e.g., site (110) or service (411)) that theactivity is suspicious or should be rejected/blocked/declined.

If the graph score is below the threshold, the controller (591) bypassesthe operations (591 and 593). Thus, the use of the graph score againstthe threshold improves the overall efficiency of the system and/or theaccuracy of the system in detecting fraudulent accesses.

FIG. 24 shows a method of access control based on a graph scoreaccording to one embodiment. For example, the method of FIG. 24 can beimplemented in a controller (101) of FIG. 4 in a system of FIG. 1 usinga relation graph (239) of FIG. 6 and/or FIG. 22.

In FIG. 24, the controller (101) is configured to store (601) graph datarepresenting a graph (239) that has: nodes representing data elementsidentified in input data about accesses made using access tokens on userdevices; and links connecting the nodes.

In response to receiving (603) input data specifying details (425) of anaccess (423) made using an access token (403), the controller (101)updates (605) the graph (239) according to the input data and determines(607) a plurality of measurements of the graph (239). After computing(609) a score of the graph (239) based on a weighted average of themeasurements, the controller (101) processes (611) the access (423) madeusing the access token (403) based on a risk represented by the score.

In one embodiment, the controller (101) for user authentication andaccess control has: at least one microprocessor (145); a networkinterface (143) controlled by the at least one microprocessor (145) tocommunicate over a computer network (100) with at least one computingsite (110); and memory (160) coupled with the at least onemicroprocessor (145).

The memory (160) stores graph data representing a graph (e.g., 239)having: nodes representing data elements associated with accesses madeusing access tokens; and links among the nodes representing connectionsbetween the data elements identified in collected data about theaccesses.

The memory (160) further stores instructions which, when executed by theat least one microprocessor, cause the controller (101) to: receive,from the computing site (110), input data specifying details (425) of anaccess (423) made using an access token (403); update the graphaccording to the input data; determine a plurality of measurements ofthe graph (239); compute a score of the graph (239) based on a weightedaverage of the measurements; and process the access made using theaccess token based on the score.

For example, when the score is above a threshold, the controller (101)communicates with the computing site (110) to block or reject the access(423), or flag the access (423) for further or future investigation.

In one embodiment, the controller (101) adjusts the weights used in theweighted average by machine learning from historic events of access.Different sets of weights can be generated/customized for differenttypes of access control applications, such as customer onboarding, frauddetection, illegal activity detection, screening for illegal orfraudulent activities based on sanction information, etc.

Examples of the measurements include a depth of the graph (239), abreadth of the graph (239), a growth rate (383) of the graph (239), atotal count of user identities in the graph (239), a count of useridentities that are in the graph (239) and have a predetermined type(e.g., based on tags assigned to the nodes representing the useridentities, based on identifying user identities being on a list of apredetermine category, such as a fake user identity list or a suspicioususer identity list, or based on a reputation attribute of useridentities)

In some instances, the graph (239) is defined by one or more statisticalboundaries; and the controller (101) determines whether new elementsfrom the input data can fit within the statistical boundaries. If not,the controller (101) dynamically adjusts the statistical boundaries toaccommodate insertion of nodes in the graph (239) according to the inputdata.

In other instances, the graph (239) can be identified for the updatebased on the access token (403), the identified user identity (401) ofthe access (423), and/or the identified device identity (409) of theaccess. In some instances, the graph (239) is generated based on acluster of access activities after a cluster analysis is performed toidentify the cluster from a large set of access activities. In someinstances, the graph (239) is extracted from a larger graph generatedfrom a large set of access activities, wherein the extraction is basedon a node of interest selected according to the input data and apredetermined number of degrees of separation from the selected node(and/or other criteria).

For example, the controller (101) can be used to perform computerizedintelligence alerts and unauthorized access detection by organizingcontextual relationship information and/or other information collectedfrom more than one source into a relation graph of data elements. Thegraph is limited to and/or identified by a set of statistical boundaryinformation. The controller (101) adjusts the statistical boundaryinformation to allow the insertion of new data elements in the graphand/or new connections between elements in the graph. When a newnode/element and/or a new connection/link/vector is added to the graph,the controller (101) evaluates a score of the graph as a whole. If thescore is above a predetermined threshold, the activity that causes theinsertion of the new information into the graph is flagged for furtherinvestigation. The score of the graph can be calculated based items suchas Total Entities in the graph, Total Entities By Type, Total EntitiesBy Reputation, Total Entities By Type By Reputation, Recent newEntities, Recent new Entities by Type, Recent new Entities ByReputation, Recent new Entities By Type By Reputation, Total Entities atcurrent Merchant, Total Entities at current Merchant By Type, TotalEntities at current Merchant By Reputation, Total Entities at currentMerchant By Type By Reputation, Total Blacklisted Entities, TotalChargeback/Fraud Refund Count, and/or previous Graph Score, etc. Also,the score be calculated further based on items such as Total number ofentities, Reputation of entities, Growth rate of the graph, Number ofnew entities recently added, Breadth of the graph, Depth of the graph,Counts of Entities on one or more blacklists, Counts of Entities onsanction lists, Counts of entities having various tags (e.g., Dropshipper tag, Fraud ring tag, Identity Theft tag). Upon flagging anactivity (e.g., a transaction), the controller issues an alert and/ortake one or more other proactive actions, such as blocking the activity,notifying transaction partners and/or authorities as needed about theactivity in question and the entity or entities involved.

Relationships among a user identity and data elements of transactionscan be identified based on information collected from one or moretransactions. The more transactions that are made, the more trustworthyan identity becomes in general. Also, the recentness and size oftransactions, as well as “arms length” helps improve the quality of theidentity rating. However, in many situations, if, for example, peopleshare computers, or work credit cards, or work shipping addresses, theiridentities may inadvertently be linked, polluting the data and reducingthe overall quality.

The present disclosure further provides a system and method to demarcategraphs between entities or individuals that may share certain resources,but still are separate individuals or entities.

FIG. 27 shows an exemplary simple graph 2700 of data elements, accordingto one aspect of the system and method disclosed herein. In graph 2700,user access context (UAC) 2701 is linked by association to paymentinstrument (PI) 2702, device identity (DI) 2703, and address for billing(ADb) 2704. This type of graph can be created for a single user orentity and needs no further demarcation. A user access context (UAC)2701 is typically but not exclusively derived from information providedduring the creation of an account in its most rudimentary form.

FIG. 28 shows an exemplary graph 2800, which is an enhanced or expandedversion of FIG. 27. After a number of uses, additional destinations havebeen used. Added are data elements UAC2 2805 and PI2 2806. These two newdata elements are shown in FIG. 28 without shading, to differentiatethem from the original data elements (PI, DI, and ADb) of FIG. 27. It ispossible that new data element UAC2 2805 may be for the same person asUAC 2801, but the person may be using a different email or spelling oftheir name; or UAC 2801 may even be a different person. Likewise, PI22806 may be the same as PI 2802, or it may be a different paymentinstrument. For example, person A (UAC 2801) and possible person B (UAC22805) may sit in the same office and use some of the same equipment,such as a certain computer and a certain company credit card. Or theymay use an entirely different computer and credit card. Such differencesmay not be easily distinguishable from the system side without furtherinvestigation or analysis.

FIG. 29 shows an exemplary graph 2900, which is a further enhancedversion of FIG. 28. In this case, additional payment instrument PI3 2902may be a second credit card that is clearly linked to the original UAC2901, and so the data element is shaded to the same degree as theoriginal UAC 2901.

FIG. 30 shows a graph 3000, continuing the series of exemplary graphsshown in FIGS. 27-29. In FIG. 30, UAC3 3008 represents a possible personC. However, UAC3 and new payment instrument PI4 3009 are linked to ADb3005. For example, Person A, B or C may use a different company paymentinstrument PI4 3009 in a different place, such as a restaurant, payingfor a business meal, and they may create a new UAC3 3008. All other dataelements are the same, and again, it is not easily distinguishable fromsystem side without further investigation or analysis whether UAC3 issame person or a different person.

FIG. 31 shows an exemplary graph 3100, with even more data elementsadded to the elements of FIG. 30. Linked to ADb 3105 is now UAC4 3110,representing a possible person D, which is linked to ADb 3105 byactivity; and extending from UAC4 3100 are payment instruments PI5 3111a-n, ADb2 3112, which could be, for example, a home address or anotherbusiness address, and another device identity DI2 3113.

FIG. 32 shows an exemplary graph 3200 of all the data elements of FIG.31, with the addition of three zone demarcation lines 3220, 3221, and3222. These three lines mark the boundaries or demarcations of areas ofinterest that may be examined to determine whether another person orpersons may or may not have intruded into identity graph 3200. Thisexamination may be undertaken by analyzing relationships among the dataelements in the graph in the original area encompassing data elements3201 through 3105 and then examining relationships of data elements inthe new zones denoted by demarcation lines 3220, 3221, and 3222.

FIG. 33 shows an exemplary software process 3300, according to oneaspect of the system and method disclosed herein. Process 3300 may beused to analyze data elements in zones such those within demarcationlines shown in FIG. 32, above, to help decide whether the data elementsin each new zone belong to the original graph in the example above ofFIG. 32 around UAC 3201 or should be put into a new separate graph andsplit off, along any and all of the demarcation lines 3220, 3221 and3222 in the above example and each turned into possible new graphs oftheir own. In some cases additional considerations may be used, asdiscussed throughout this document, including but not limited to anadditional manual review, etc. Process 3300 may be activated either atregular intervals, such as, for example, during a nightly update of allaccount data; or upon new account activity, such as, for example,whenever a new data element is added to the graph. Upon receipt of anyexternal trigger via input means 3304, the system first examines thegraph. In step 3301 the system loads data from data store 3320. In step3302, the system creates a list of data elements in the original graph,such as, for example, the graph shown in FIG. 31. In step 3303, thesystem creates a list of data elements in each additional zone, as shownin exemplary FIG. 32. For each separate zone, the system creates aseparate sublist, because the relationships and activities of the dataelements within each zone are not linked interzonally. It is possiblethat the activities within each zone could be from a different person,are unrelated, and thus must be examined separately. For each sublist1−n created in step 3303, the system in step 3305 calculates a scorebased on the data of each data element. Scoring is accumulated based onwhether the new data elements match the data elements of the originalgraph. Data elements may include, but are not limited to, examples suchas these: Payment method—same name of person? Social security numberassociated with payment method—same number? Same billing address? Sameshipping address? Many factors may be considered, depending onavailability of data. Note that each sublist 1−n may contain a differentnumber of data elements, but the score per element may be the same.Thus, if one list contain two data elements and another list contain 10elements, the lists will have different scores, but the score per dataelement may be the same or different. In step 3306 the system checkseach score to determine whether it exceeds a preset threshold per dataelement. If the score exceeds the threshold, the system considers thatthe data elements in that zone are the result of activities by the sameperson whose data elements are in the original graph. If the score doesnot exceed the threshold, the system considers that the data elementsbelong to a different person. Depending on the system's determinations,the system stores the data in data store 3320 as being that of the sameperson, in step 3307, or that of a different person, in step 3308. Instep 3309 the system increments the count of sublists by one until thecount (y) reaches the number (n) of sublists created in step 3303. If ydoes not equal n, the system returns to step 3305; when y=n, the processmoves to the end in step 3311.

In some cases, a system may analyze graphs created for digital identityverification. These graphs contain data element nodes collected about anindividual's activities, including data about, for example, user accesscontext (UAC), payment instrument (PI), address information for billing(ADb), address information for shipping (ADs), device information (DI),Internet protocol address (IPa), etc. Nodes may be added based onassociation or relations from interactions including transactions. Fromtime to time the graph is examined, and suspected duplicate nodes aresegregated into demarcation areas. The system may then analyze nodesclosely for the identity of the person behind the activity, calculatinga score to determine the relative confidence of whether any new activityis caused by the same person as the person in the main graph or not,based on a detailed analysis of all available information, including butnot limited to such as exact or close mathematical variations ofspelling of the name, exact or close mathematical variations of billingaddress, exact or close mathematical variations of shipping address,Email address, phone number, date of birth, account name, national id(e.g., social security number) etc.

Further, in some cases, there are cross-links between nodes that canmake things a bit more complicated. As it pertains to FIG. 32 forexample, a link might exist between element 3213 and 3221 (not shown)that might indicate that those demarked zones 3222 and 3221 might belongtogether. Further, additional weak links between far elements, forexample 3213 and 3201 (not shown) could mean that there might be or notbe a link. Weak links might be coincidental or circumstantial linksrather than firm links by actual transaction and can therefore bediscounted somewhat, unless they occur in very high frequency etc.Different weights might be used to filter such far and weak links andsuch reduce the noise in the algorithmic approach such as discussed inFIG. 33 above, anywhere throughout or similar.

For example, a relation graph can be stored to identify the relations ofdata elements that are connected via transactions. In the relation graphthe data elements are represented by nodes; and the relations among thedata element are represented by links, edges or connections among nodesin the relation graph. In general, a relation graph as illustrated inFIG. 8 or FIG. 31 includes nodes of data elements that belong todifferent users.

The relation graph can be analyzed in a way as discussed above and/orfurther discussed below to extract, from the relation graph, graphlets,where each graphlet contains data elements that are attributed to aparticular user. The user may be identified via one or more nodes of thetype of user access context. Nodes of data elements in the relationgraph that are likely to be attributes of other users are removed fromthe graphlet of the particular user. Graphlets of different users mayshare a set of nodes of data elements but generally do not share nodesof the type of user access context.

In the relation graph illustrated in FIG. 31, a user access context node(e.g., 3101) may be connected to another user access context nodes(e.g., 3106) directly and be connected to a further user access context(e.g., 3108 or 3110) indirectly. The different user access context nodes(e.g., 3101, 3106, 3108, 3110) can correspond to different electronicsignatures that do not completely match with each other.

The matching scores and/or trust scores between electronic signatures oftransactions can be computed to initially identify core data elementnodes (e.g., 3101, 3102, 3103, 3104, 3105) of a user access context node(e.g., 3101). For example, when one or more transactions have electronicsignatures that are identified with the user access context node (3101),the data elements (e.g., 3102, 3103, 3104, 3105) of the one or moretransactions are identified as the core data elements (e.g., 3101, 3102,3103, 3104, 3105) of the user access context node (e.g., 3101). A groupof core data element nodes is illustrated as shaded nodes in FIGS.27-32.

Other transactions may identify other groups of core data element nodes.For example, one group of core data elements includes nodes (3106 and3107); another group of core data elements includes nodes (3108, 3109and 3105); and a further group of core data elements includes nodes(3110, 3111 a-n, 3112, 3113, and 3103).

The groups of core data elements may connect to each other via shareddata element nodes (e.g., 3103, 3105) and/or connections between useraccess context nodes (e.g., connection between 3101 and 3106).

For example, when the matching scores and/or trust scores betweenelectronic signatures of transactions associated with the user contextnodes (3101 and 3106) are in a predetermined range, the user contextnodes (3101 and 3106) can be identified as being connected via anedge/connection/link in the relation graph illustrated in FIG. 31.Whether the user context nodes (3101 and 3106) belong to a graphlet of asame user can be determined based on a matching score of the core dataelements of the user context nodes (3101 and 3106) as further discussedbelow.

The groups of core data element nodes centered at the user accesscontext nodes (3101 and 3108) respectively share a same node (3105) andthus connected to each other via the shared node (3105).

Similarly, the groups of core data element nodes centered at the useraccess context nodes (3101 and 3110) respectively share at least onesame node (3103) and thus connected to each other via the shared atleast one node (3103).

When the groups of core data element nodes (e.g., centered at the useraccess context nodes 3101, 3106, 3108 and 3110) are connected in therelation graph as illustrated in FIG. 31, the groups of core dataelement nodes may or may not belong to a same user.

To determine whether a group of core data element nodes (e.g., centeredat the user access context node 3101) and another group of core dataelements (e.g., centered at the user access context node 3106, 3108, or3110) can be attributed to a same user, a matching score between thegroups of nodes is computed.

To compute the matching score between the node groups, nodes of matchingtypes between the groups are identified for comparison. For example, theuser access context node (3101) is compared with the user access contextnode (3106, 3108, or 3110). For example, the payment instrument nodes(3102 or 3103) of the user access context node (3101) is compared to thepayment instrument node (3107) of the user access context node (3106),the payment instrument node (3109) of the user access context node(3108), or the payment instrument node (3111 a-n, or 3103) of the useraccess context node (3110). For example, the device information node(3104) of the user access context node (3101) is compared to the deviceinformation node (3113) of the user access context node (3110).

The data elements of nodes in each pair of a matching type are comparedto each other to generate a similarity score. For example, a similarityscore can be generated from comparing two user access context nodes(e.g., 3101 and 3106; 3101 and 3108; or 3101 and 3110) based on the datafields of the user access context nodes. For example, a similarity scorecan be generated from comparing two device information nodes (e.g., 3104and 3113) based on the data fields in the respective device informationnodes. For example, a similarity score can be generated from comparingtwo payment instrument nodes (e.g., 3103 and 3107; 3102 and 3107; or3102 and 3109) based on the data fields in the respective paymentinstrument nodes.

A matching score between two groups of core data element nodes (e.g.,centered at nodes 3101 and 3106 respectively, or nodes 3101 and 3108respectively, or nodes 3101 and 3110 respectively) can be computed bysumming the similarity scores of pairs of nodes of matching types anddividing the sum by the number based on the node counts of the groups togenerate an average.

In one embodiment, the smaller one of the node counts of the groups isused to compute the average. Alternatively, the larger one of the nodecounts of the groups is used to compute the average. Alternatively, asum of the node counts of the groups can be used to compute the average.

For example, when considering whether a second group of nodes (e.g.,centered at 3106) is to be included in the graphlet containing a firstgroup (e.g., centered at 3101), the node count of the second group ofnodes (e.g., centered at 3106) is used to compute the average of thesimilarity scores.

When the matching score between two groups of core data element nodes(e.g., centered at nodes 3101 and 3106 respectively, or nodes 3101 and3108 respectively, or nodes 3101 and 3110 respectively) is above athreshold, the two groups of core data element nodes are placed in asame graphlet for a particular user; and the data elements in thegraphlet are considered to be attributes of the particular user.

Thus, based on the matching scores of the groups, some of the groups ofcore data element nodes centered at related user access context nodes(3106, 3108, 3110) may be placed in the same graphlet of the user of thegroup of core data element nodes centered at the user access contextnode (3101); and other groups are excluded from the graphlet. Theresulting graphlet contains data elements of a particular user and canbe used for digital identity verification.

For example, the graphlet of a particular user can be used to constructan existing electronic signature of the user; and in response to arequest to verify the identity of a current user making an access, theinformation about the current user making the access can be used toconstruct a current electronic signature. The identity of the currentuser making the access can be verified based on a matching score and/ortrust score of the current electronic signature measured against to theexisting electronic signature.

For example, after a graphlet of a particular user is identified from arelation graph in a way as discussed above, the controller (101) of FIG.1 can use the electronic signature generated according to the graphletof the particular user to determine whether a current user making anaccess is the particular user of the graphlet in user authenticationand/or control access.

For example, a controller for user authentication and access control caninclude at least one microprocessor, a network interface controlled bythe at least one microprocessor to communicate over a computer networkto receive information related to accesses made in the past using accesstokens, and memory coupled with the at least one microprocessor andstoring graph data and instructions.

The graph data represents a relation graph having nodes and links; thenodes represent data elements found the information related to theaccesses made using the access tokens; and the links connect the nodesto represent connections between the data elements found in theinformation related to the accesses made using the access tokens.

The instructions, when executed by the at least one microprocessor,cause the controller to perform a method that includes identifying aplurality of groups of nodes in the relation graph. Nodes in each groupbelong to a user; nodes in a first group in the plurality of groupsbelong to a particular user; and the plurality of groups are connectedin the relation graph.

To determine whether or not other groups in the plurality of groupsbelong to the particular user of the first group, the method includesidentifying a subset of the plurality of groups as belonging to theparticular user of the first group, by at least: computing a matchingscore between the first group in the plurality of groups and a secondgroup in the plurality of groups; comparing the matching score with athreshold; and determining whether or not the second group belongs tothe particular user of the first group based on whether or not thematching score between the first group and the second group is above thethreshold.

The method can further include: constructing a graphlet from the subset,where nodes in the graphlet are determined to represent data elements ofthe particular user of the first group; and constructing an electronicsignature of the particular user based on the graphlet. In response toreceiving data of a particular access, the method can further include:authenticating the particular access based on comparing the electronicsignature constructed from the graphlet and an electronic signatureconstructed from the data of the particular access.

For example, each of the plurality of groups can include a respectivenode representing user access context; and the nodes in the relationgraph can include: nodes of a type of billing addresses; nodes of a typeof shipping addresses; nodes of a type of payment instruments; nodes ofa type of internet protocol addresses; nodes of a type of deviceinformation; and/or nodes of a type of user access context.

For example, each of the plurality of groups can be identified toinclude nodes representing data elements associated with accesses madein the user access context represented by the respective node.

The first group and the second group can be connected to each other inthe relation graph via at least a link between a user access contextnode in the first group and a user access context node in the secondgroup. The link may indicate that, and/or be established based on that,a matching score between an electronic signature associated with theuser access context node in the first group and an electronic signatureassociated with the user access context node in the second group iswithin a predetermined range. Alternatively, the link may indicate that,and/or be established based on that, a similarity score between the useraccess context node in the first group and the user access context nodein the second group is within a predetermined range.

The first group and the second group can be connected to each other inthe relation graph by sharing at least one data element node that is notof a type of user access context.

The matching score between the first group and the second group can becomputed by, for example: identifying pairs of nodes of matching typesbetween the first group and the second group; and computing a similarscore between each pair in the pairs of nodes of matching types; andsumming the similarity scores of the pairs of nodes of matching types.

The matching score can be proportional to a sum of the similarity scoresdivided by a count of nodes in the second group, or proportional to asum of the similarity scores divided by a count of nodes in the firstgroup, or proportional to a sum of the similarity scores divided by asum of a node count of the first group and a node count of the secondgroup.

A matching score between the electronic signature constructed from thegraphlet and the electronic signature constructed from the data of theparticular access can be computed from comparing of the electronicsignature constructed from the graphlet and the electronic signatureconstructed from the data of the particular access.

For example, the matching score between the electronic signatureconstructed from the graphlet and the electronic signature constructedfrom the data of the particular access can be computed based on a sum ofweights assigned to matched attributes between the electronic signatureconstructed from the graphlet and the electronic signature constructedfrom the data of the particular access, a sum of weights assigned tomismatched attributes between the electronic signature constructed fromthe graphlet and the electronic signature constructed from the data ofthe particular access, and/or a sum of weights assigned to attributes inthe electronic signature constructed from the graphlet but not theelectronic signature constructed from the data of the particular access.

FIG. 25 shows a computing apparatus that can be used to implement thedevices, sites, controllers and/or servers discussed in the presentdisclosure. The computing apparatus can be configured with programinstructions and relevant data to implement a computing device (e.g.,120, 121, 123, . . . , 125, . . . , 129) or a computing site (e.g., 110,111, 113, . . . , 119), or the controller (101).

In FIG. 25, the computing apparatus includes a bus (481), a CPU (145),memory (160) and nonvolatile memory (NVM) (483) for holding programs andstart-up code, etc., an input/output (I/O) section (482), a mass storagedevice (487) that can hold additional codes such as operating systems,applications, data, etc., and and a network interface (s) (143), whichmay accommodate any of three groups (473, 475, 477) of networkconnections, such as wired local area network (LAN) connections (473),wireless local area network (WLAN) connections (475), and wide areanetwork (WAN) connections (477).

Examples of wired LAN connections (473) include, but not limited to,Ethernet, serial port, FireWire, Thunderbolt, etc.

Examples of WLAN connections (475) include, but not limited to, Wi-Fi,Bluetooth, Zigbee, ultra wideband, etc.

Examples of WAN connections (477) include, but not limited to, cellularnetwork connections of various different types using various differentbands.

The computing apparatus of FIG. 25 may optionally include a display(486). Data input can be accomplished via an input device (485), whichmay be a touch screen, a physical keyboard, or both.

The computing apparatus of FIG. 25 may optionally include a pointingdevice (484), such as a mouse, a touch pad, a touch screen, a joy stick,or any combinations thereof.

The computing apparatus of FIG. 25 may optionally include other I/Odevices, such as a speaker (488), a microphone (489), a camera, a thumbscanner, etc.

The input/output devices (e.g., 484-489) are connected to the bus (481)via the I/O section (482).

The computing apparatus of FIG. 25 can be configured in one of a widevariety of types, including, for example, a smart phone, a digital mediaplayer, a personal digital assistant, a computer pad, a laptop, adesktop, a work station, a server, etc.

The computing apparatus of FIG. 25 can be configured at least in partvia software instructions to perform any of the methods disclosedherein. The present disclosure also includes non-transitory computerstorage media storing the software instructions which, when executed onthe computing apparatus, cause the computing apparatus to perform any ofthe methods.

FIG. 26 shows a block diagram of a computing infrastructure associatedwith certain embodiments of the present disclosure. The computinginfrastructure of FIG. 26 can be used to provide the services offered bythe computing sites (110, 111, 113, . . . , 119) and/or the controller(101) connected by the network (100).

In FIG. 26, the computing infrastructure includes a server (495) whichmay be a single physical server or a cluster (490) of many smallerservers (499). These server(s) (490 or 499) can contain multiple sets ofcodes (496), including multiple operating systems, on top of which maybe multiple applications (498) and additional multiple data sets (497)in storage. Client computing devices (493, . . . , 494), as well asdesktop devices (e.g., 492), connect to the server (495) via Internet(491).

Functionally a desktop computer is very similar to a smart phone, exceptthat the relationship between performance and display and operatingsystem, etc. is different; and a desktop computer has typically a muchlarger display.

Also, in the server (495), whether a single server or a cluster (490),each node is a specialized version of a computing apparatus (e.g.,illustrated in FIG. 25). The cloud computer arrangement of FIG. 26enables applications (498) to cooperate between one or more of theclient devices (493, . . . , 494) and the cloud represented by theserver (495), where some functionality is performed in the cloud andsome is on the device.

Further, it may not always be predetermined as to what operations arebeing done where, and operation locations can vary from situation tosituation, as well as varying according the capabilities of the clientcomputing device (e.g., 493, . . . , 494) involved.

In the foregoing specification, the disclosure has been described withreference to specific exemplary embodiments thereof. It will be evidentthat various modifications may be made thereto without departing fromthe broader spirit and scope as set forth in the following claims. Thespecification and drawings are, accordingly, to be regarded in anillustrative sense rather than a restrictive sense.

What is claimed is:
 1. A controller for user authentication and access control, the controller comprising: at least one microprocessor; a network interface controlled by the at least one microprocessor to communicate over a computer network to receive information related to accesses made using access tokens; memory coupled with the at least one microprocessor and storing graph data and instructions; wherein the graph data represents a relation graph having nodes and links; wherein the nodes represent data elements found in the information related to the accesses made using the access tokens; wherein the links connect the nodes to represent connections between the data elements found in the information related to the accesses made using the access tokens; and wherein, when executed by the at least one microprocessor, the instructions cause the controller to: identify a plurality of groups of nodes in the relation graph, wherein nodes in each group belong to a user, nodes in a first group in the plurality of groups belong to a particular user, the plurality of groups are connected in the relation graph, and it is to be determined whether or not the plurality of groups belong to the particular user of the first group; identify a subset of the plurality of groups as belonging to the particular user of the first group, by at least: computing a matching score between the first group in the plurality of groups and a second group in the plurality of groups; comparing the matching score with a threshold; and determining whether or not the second group belongs to the particular user of the first group based on whether or not the matching score between the first group and the second group is above the threshold; construct a graphlet from the subset, wherein nodes in the graphlet are determined to represent data elements of the particular user; construct an electronic signature of the particular user based on the graphlet; receive data of a particular access; and authenticate the particular access based on comparing the electronic signature constructed from the graphlet and an electronic signature constructed from the data of the particular access; and wherein the comparing the electronic signature constructed from the graphlet and the electronic signature constructed from the data of the particular access includes computing a matching score between the electronic signature constructed from the graphlet and the electronic signature constructed from the data of the particular access.
 2. The controller of claim 1, wherein each of the plurality of groups includes a respective node representing user access context.
 3. The controller of claim 2, wherein the nodes in the relation graph include: nodes of a type of billing addresses; nodes of a type of shipping addresses; nodes of a type of payment instruments; nodes of a type of interne protocol addresses; nodes of a type of device information; and nodes of a type of user access context.
 4. The controller of claim 2, wherein each of the plurality of groups is identified to include nodes representing data elements associated with accesses made in the user access context represented by the respective node.
 5. The controller of claim 4, wherein the first group and the second group are connected to each other in the relation graph via at least a link between a user access context node in the first group and a user access context node in the second group.
 6. The controller of claim 5, wherein the link indicates that a matching score between an electronic signature associated with the user access context node in the first group and an electronic signature associated with the user access context node in the second group is within a predetermined range.
 7. The controller of claim 5, wherein the link indicates that a similarity score between the user access context node in the first group and the user access context node in the second group is within the predetermined range.
 8. The controller of claim 4, wherein the first group and the second group are connected to each other in the relation graph by sharing at least one data element node that is not of a type of user access context.
 9. The controller of claim 2, wherein the matching score between the first group and the second group is computed by: identifying pairs of nodes of matching types between the first group and the second group; and computing a similar score between each pair in the pairs of nodes of matching types; and summing the similarity scores of the pairs of nodes of matching types.
 10. The controller of claim 9, wherein the matching score is proportional to a sum of the similarity scores divided by a count of nodes in the second group.
 11. The controller of claim 9, wherein the matching score is proportional to a sum of the similarity scores divided by a count of nodes in the first group.
 12. The controller of claim 9, wherein the matching score is proportional to a sum of the similarity scores divided by a sum of a node count of the first group and a node count of the second group.
 13. The controller of claim 1, wherein the matching score between the electronic signature constructed from the graphlet and the electronic signature constructed from the data of the particular access is based on a sum of weights assigned to matched attributes between the electronic signature constructed from the graphlet and the electronic signature constructed from the data of the particular access.
 14. The controller of claim 13, wherein the matching score between the electronic signature constructed from the graphlet and the electronic signature constructed from the data of the particular access is further based on a sum of weights assigned to mismatched attributes between the electronic signature constructed from the graphlet and the electronic signature constructed from the data of the particular access.
 15. The controller of claim 14, wherein the matching score between the electronic signature constructed from the graphlet and the electronic signature constructed from the data of the particular access is further based on a sum of weights assigned to attributes in the electronic signature constructed from the graphlet but not the electronic signature constructed from the data of the particular access.
 16. A non-transitory computer storage medium storing instructions which, when executed by a controller, cause the controller to perform a method for user authentication and access control, the method comprising: receiving information related to accesses made using access tokens; generating from the information a relation graph having nodes and links, wherein: the nodes represent data elements found in the information related to the accesses made using the access tokens, and the links connect the nodes to represent connections between the data elements found in the information related to the accesses made using the access tokens; identifying a plurality of groups of nodes in the relation graph, wherein nodes in each group belong to a user, nodes in a first group in the plurality of groups belong to a particular user, the plurality of groups are connected in the relation graph, and it is to be determined whether or not the plurality of groups belong to the particular user of the first group; identifying a subset of the plurality of groups as belonging to the particular user of the first group, by at least: computing a matching score between the first group in the plurality of groups and a second group in the plurality of groups; comparing the matching score with a threshold; and determining whether or not the second group belongs to the particular user of the first group based on whether or not the matching score between the first group and the second group is above the threshold; constructing a graphlet from the subset, wherein nodes in the graphlet are determined to represent data elements of the particular user; constructing an electronic signature of the particular user based on the graphlet; receiving data of a particular access; and authenticating the particular access based on comparing the electronic signature constructed from the graphlet and an electronic signature constructed from the data of the particular access, and comparing the electronic signature constructed from the graphlet and the electronic signature constructed from the data of the particular access includes computing a matching score between the electronic signature constructed from the graphlet and the electronic signature constructed from the data of the particular access.
 17. A method for user authentication and access control, the method comprising: receiving information related to accesses made using access tokens; generating from the information a relation graph having nodes and links, wherein: the nodes represent data elements found in the information related to the accesses made using the access tokens, and the links connect the nodes to represent connections between the data elements found in the information related to the accesses made using the access tokens; identifying a plurality of groups of nodes in the relation graph, wherein nodes in each group belong to a user, nodes in a first group in the plurality of groups belong to a particular user, the plurality of groups are connected in the relation graph, and it is to be determined whether or not the plurality of groups belong to the particular user of the first group; identifying a subset of the plurality of groups as belonging to the particular user of the first group, by at least: computing a matching score between the first group in the plurality of groups and a second group in the plurality of groups; comparing the matching score with a threshold; and determining whether or not the second group belongs to the particular user of the first group based on whether or not the matching score between the first group and the second group is above the threshold; constructing a graphlet from the subset, wherein nodes in the graphlet are determined to represent data elements of the particular user; constructing an electronic signature of the particular user based on the graphlet; receiving data of a particular access; and authenticating the particular access based on comparing the electronic signature constructed from the graphlet and an electronic signature constructed from the data of the particular access, and comparing the electronic signature constructed from the graphlet and the electronic signature constructed from the data of the particular access includes computing a matching score between the electronic signature constructed from the graphlet and the electronic signature constructed from the data of the particular access.
 18. The method of claim 17, wherein the computing of the matching score between the first group and the second group includes: identifying pairs of nodes of matching types between the first group and the second group; and computing a similar score between each pair in the pairs of nodes of matching types; and determining an average of the similarity scores of the pairs of nodes of matching types.
 19. The method of claim 18, wherein the average of the similarity scores is based on at least one of: a node count of the first group and a node count of the second group. 